Hazardous Agents Research Articles

Comparative Investigation of Electrocatalytic Oxidation By Proton-Exchange-Membrane and Anion-Exchange-Membrane Electrolyses

Oxidation is one of the most important reactions in chemical industries. However, the oxidation reaction generally requires a large input energy and problematic oxidants. On the other hand, the electrochemical oxidation is expected to be a key technology for the reduction of greenhouse gas emissions because this reaction can generally be performed under mild conditions. In addition, it does not require any hazardous redox agents and produce less waste than other conventional oxidation processes [1]. However, electrochemical oxidation also has some disadvantages. In order to provide sufficient conductivity, a large amount of supporting electrolyte is usually required. The presence of the supporting electrolyte might cause separation problems in the reaction workup. Moreover, in an ordinary electrolysis system, solution resistance is generated between the working and counter electrodes, resulting in a decrease in energy efficiency [2]. In addition, it is difficult to realize direct oxidation of hydrocarbons because their redox potentials are higher than those of solvents and electrolytes [3].To overcome these problems, we focused on a solid polymer electrolyte (SPE) electrolysis technologies. The SPE electrolysis cell was originally developed for fuel cell technologies. As shown in Figure, a membrane electrode assembly (MEA) is integrated into the central part of the reactor. The MEA consists of an ion exchange membrane sandwiched between a pair of catalyst layers on the anode and cathode sides, having the dual roles of electrode. For this reason, the substrate solution does not require a supporting electrolyte and the cell resistance can be minimized. Furthermore, the oxidative conversion can be carried out at a potential lower than that required to effective its direct electrooxidation because it uses reactive oxygen species generated on the anode catalyst from H2O.The main types of SPE electrolysis technologies are proton exchange membrane (PEM) electrolysis and anion exchange membrane (AEM) electrolysis. The former PEM has been used widely as a fuel cell and a water electrolysis equipment. However, because of acidic environment at the electrochemical reaction fields, it may cause undesired side reactions. Moreover, electrocatalysts are limited to some noble metals. On the other hand, in the later AEM, many earth-abundant metal catalysts can be used because of its alkaline environment [4,5]. However, the durability of AEM is not yet suitable for commercialization. With these in mind, in this work, we have demonstrated electrocatalytic oxidation of cyclohexene by using both PEM and AEM electrolyzers. We have also optimized the applied voltage and selected the suitable anode catalyst to realize highly selective and efficient oxidation process.The authors gratefully acknowledge support by JST CREST Grant No. JPMJCR18R1, Japan.

Biosensors for toxic metals, polychlorinated biphenyls, biological oxygen demand, endocrine disruptors, hormones, dioxin, phenolic and organophosphorus compounds: a review

The growing pollution by hazardous agents is a major concern due to pollutant transfer to water, air, soil and food. Since actual analytical methods are limited, there is a need for detectors that are more sensitive, more selective, faster and cheaper. For instance, advanced portable biosensors have better sensitivity compared to classical diagnostic devices. Here, we review ultrasensitive detection of pollutants by biosensors. In particular, nanobiosensors display remarkable nanomolar to picomolar detection of various pollutants including heavy metals, pesticides, endocrine disruptors, dioxin, biological oxygen demand and microbial pathogens.

Occupational exposures to hazardous chemicals and agents among healthcare workers in Bhutan

Occupational exposures to hazardous chemicals among healthcare workers can result in long-term adverse health outcomes. Research on such exposures from low- and middle-income countries is limited. The aim of this study was to estimate the prevalence of exposures to a range of chemicals used in healthcare settings among Bhutanese healthcare workers. A cross-sectional study was conducted among healthcare workers (n = 370) working in three hospitals in the western region of Bhutan. Demographic and occupational information was collected, and exposures to asthmagens, carcinogens, ototoxic and other agents were assessed using a web-based tool. The prevalence of exposure to these chemicals was calculated and the circumstances resulting in such exposures were examined. The prevalence of exposure to one or more asthmagen, carcinogen, and ototoxic agent was 98.7%, 28.1%, and 7.6%, respectively; and was 6.2% for anesthetic gases and 2.2% for antineoplastic drugs. The most common exposures were to latex, and cleaning and disinfecting agents in the asthmagens group; formaldehyde in the carcinogens group; and p-xylene among ototoxic agents. The circumstances resulting in exposures were using latex gloves, using bleach and chlorhexidine for cleaning, using formaldehyde as a disinfectant and in the laboratory, and using p-xylene in the laboratory. The results indicate that a large proportion of Bhutanese healthcare workers are occupationally exposed to chemicals linked to chronic diseases, with exposure prevalence higher than in high-income countries. The study provides information that can be used to formulate policies and to implement control measures to protect healthcare workers.

Simultaneous Square Wave Voltammetric Detection of Endocrine-Disrupting Agents Using a Nanocomposite of Magnetic Fe3O4Nanorods and Poly(3,4-Methylenedioxy)aniline

In this report, the ultrasensitive simultaneous determination of bisphenol A (BPA), phenol, and 4-nitrophenol (4-NP) as hazardous phenolic endocrine-disrupting agents was explored by square wave voltammetry (SWV) using magnetic “needlelike” Fe3O4 nanorods (MNRs) and a poly(3,4-methylenedioxy)aniline (PMDAN) nanocomposite-modified graphite paste electrode (GPE). The MNRs had dimensions of 5.3 ± 1.1 nm in width and 61.4 ± 3.3 nm in length. A solid-state, green, and sustainable method incorporating mechanochemical reactions between 3,4-(methylenedioxy)aniline as a novel aniline monomer and Fe(III) chloride was used for the synthesis of MNR-PMDAN. The MNR-PMDAN nanocomposite-modified GPE (MNR-PMDAN/GPE) exhibited three well-defined anodic peaks at 0.82, 0.96, and 1.20 V vs Ag/AgCl for BPA, phenol, and 4-NP, respectively, in an acidic electrolyte solution at pH 2.0. The calibration curves were linear up to 40.0, 150.0, and 125.0 μM with a limit of detection of 4.3, 15.3, and 16.8 nM for BPA, phenol, and 4-NP, respectively. MNR-PMDAN/GPE was also used for the determination of BPA, phenol, and 4-NP in real samples with recoveries in the range of 95.2–104.9%. The results of this study demonstrate that the MNR-PMDAN nanocomposite is suitable for applications toward the development of a handheld device for on-field prescreening of hazardous endocrine-disrupting pollutants.

Occupational exposure to inorganic lead and its compounds in Romania

Abstract Lead and its compounds are hazardous chemical agents; some lead compounds, are classified as carcinogens in humans. In Romania, the occupational exposure to inorganic lead and its compounds occurs in many sectors: production of lead, manufacture of batteries, manufacture of thermal ceramic products (terracotta), production of electric and electronic components, manufacture of articles of metal wire, production of dyes and additives for plastics, recovery of lead from waste batteries, waste collection and treatment of electrical and electronic equipment, etc. The binding occupational limit value for inorganic lead compounds established under the national regulations is 0.15 mg/m3 in the air (measured in relation to a reference period of eight hours, time-weighted average, TWA). The binding biological limit value is 70 μg Pb/100 ml blood. We have summarized lead occupational exposure data collected from the regional public health authorities in Romania, for the period 2011-2019. The concentrations of lead recorded in the workplaces air varied between “not detected” and 0.22 mg/m3. The lead concentrations in the blood had high values (over the alert value of 40 μg/100 ml blood) in several activities (production of lead, recovery-recycling of lead from waste batteries, manufacture of batteries, and manufacture of articles of metal wire) leading to the need of continuous surveillance of health status for the exposed workers.

Mesoporous Silica Platforms with Potential Applications in Release and Adsorption of Active Agents.

In recent years, researchers focused their attention on mesoporous silica nanoparticles (MSNs) owing to the considerable advancements of the characterization methods, especially electron microscopy methods, which allowed for a clear visualization of the pore structure and the materials encapsulated within the pores, along with the X-ray diffraction (small angles) methods and specific surface area determination by Brunauer–Emmett–Teller (BET) technique. Mesoporous silica gained important consideration in biomedical applications thanks to its tunable pore size, high surface area, surface functionalization possibility, chemical stability, and pore nature. Specifically, the nature of the pores allows for the encapsulation and release of anti-cancer drugs into tumor tissues, which makes MSN ideal candidates as drug delivery carriers in cancer treatment. Moreover, the inner and outer surfaces of the MSN provide a platform for further functionalization approaches that could enhance the adsorption of the drug within the silica network and the selective targeting and controlled release to the desired site. Additionally, stimuli-responsive mesoporous silica systems are being used as mediators in cancer therapy, and through the release of the therapeutic agents hosted inside the pores under the action of specific triggering factors, it can selectively deliver them into tumor tissues. Another important application of the mesoporous silica nanomaterials is related to its ability to extract different hazardous species from aqueous media, some of these agents being antibiotics, pesticides, or anti-tumor agents. The purpose of this paper is to analyze the methods of MSN synthesis and related characteristics, the available surface functionalization strategies, and the most important applications of MSN in adsorption as well as release studies. Owing to the increasing antibiotic resistance, the need for developing materials for antibiotic removal from wastewaters is important and mesoporous materials already proved remarkable performances in environmental applications, including removal or even degradation of hazardous agents such as antibiotics and pesticides.

Preparation and Chemical Protective Clothing Application of PVDF Based Sodium Sulfonate Membrane.

Chemical protective clothing (CPC) is major equipment to protect human skin from hazardous chemical warfare agents (CWAs), especially nerve agents and blister agents. CPC performance is mainly dominated by the chemical protective material, which needs to meet various requirements, such as mechanical robustness, protective properties, physiological comfort, cost-effectiveness, and dimensional stability. In this study, polyvinylidene fluoride (PVDF) based sodium sulfonate membranes with different ion exchange capacities (IECs) are prepared simply from low-cost materials. Their mechanical properties, contact angles, permeations, and selectivities have been tested and compared with each other. Results show that membranes with IEC in the range of 1.5–2 mmol g−1 have high selectivities of water vapor permeation over CWA simulant vapor permeation and good mechanical properties. Therefore, PVDF-based sodium sulfonate membranes are potential materials for CPC applications.

Recombinant Retroviral Particles: Technology of Poduction and Application as Positive Controls for PCR Diagnostics of Dangerous Viral Infections

Objective. Construction of positive control samples based on recombinant retroviral particles and their application in RT-PCR diagnostic assays for RNA detection of agents of dangerous and particularly dangerous viral infections.Materials and methods. Molecular biological, genetic engineering, and immunological methods were used: polymerase chain reaction, restriction, ligation, cloning, transformation, transfection, flow cytometry.Results and discussion. Technology of positive control samples producing based on recombinant virions has been developed and tested. It includes construction of retroviral vector with cloned diagnostic sequence of the viral genome; obtaining a packaging cell line producing chimeric retroviral particles; determination of recombinant virions titer by flow cytometry and polymerase chain reaction; application of the obtained preparation as a control sample for PCR diagnostics of infectious agents. Positive controls based on retroviral vectors as carriers of genomic RNA fragments of pathogenic viruses were used in the development of PCR diagnostic kits for dangerous and particularly dangerous viral infections. Their application increased the kits quality and made it possible to exclude the work with concentrated hazardous infectious agents (Lassa virus, tick-borne encephalitis virus, lymphocytic choriomeningitis virus, Puumala virus).

Occupational Health Risk Assessment for Benzene and hydrogen Sulfide-Exposed Posts at a Crude Oil Depot

The purpose of this study is to investigate the hazard status of benzene and hydrogen sulfide in a crude oil depot and evaluate the occupational health risk level, so as to provide countermeasures for risk control. In this study, the comprehensive index method was used to evaluate the occupational health risk level of exposure to benzene and hydrogen sulfide in the pump room, valve group, control room and tank metering port. The results show that the metrology workers are exposed to benzene and hydrogen sulfide in the process of operation of pump room, valve group, control room and tank metering port. Sanitary engineering protection measures are mainly closed operation, and set up ventilation fan in the pump room, personal protective equipment is mainly anti-static work clothes, oil-resistant gloves, respiratory protective equipment is gas masks, but they are not weared daily. The occupational health management system is complete. The working time of each shift is 12h, with a maximum of four shifts per week for 48h and a maximum of 12h per shift for exposure to chemical hazardous agents. Benzene and hydrogen sulfide were tested for 11 samples each, and the detected exposure concentration was not exceeding the standard. The hazard levels of benzene and hydrogen sulfide were grade 5 and grade 4, respectively, and the exposure level was 1.62. The risk index of exposure to benzene and hydrogen sulfide was 3, and the risk level was medium. The protective measures for the crude oil depot are effective, but the on-site monitoring of benzene and hydrogen sulfide concentration should be strengthened to prevent acute poisoning accidents and reduce occupational health risks.

CANARY Technology: Working Principles of Biosensor, Detection of Infectious Pathogens

Reusable biosensors for the detection of biochemical analytes are widely used in clinical and laboratory practice. However, biosensors for the detection of pathogenic microorganisms are still under development or implementation. One of these devices is CANARY biosensor (Cellular Analysis and Notification of Antigen Risks and Yields), used by the US Army to indicate pathogenic biological agents. The aim of this article is to consider operating principles and molecular-biological foundations of CANARY biosensor, to analyze the possible directions of work and the prospects for creating domestically made biosensors based on eukaryotic cells. The concept of CANARY is that its receptor component is a B-lymphocyte, modified using genetic engineering, which carries specific IgM-like B-cell receptors on the surface of the cytoplasmic membrane. These cells are able to specifically recognize the target antigen and generate a photosignal through the aequorin protein. Currently, biosensors are already created for the detection of causative agents of plague (100–1000 CFU / ml), tularemia (100 CFU / ml), anthrax (100–500 spores / ml), smallpox (<500 CFU / ml), some toxins (ricin – 3 ng / ml, botulinum toxin – 16 pg / ml). They are based on the CANARY biosensor. Due to high sensitivity and specificity of this method, the relative simplicity and high speed of analysis of one sample, the possibility of analyzing aerosol samples, this technology should be considered as a promising basis for the creation of domestically made biological sensors to detect hazardous biological agents in biological samples, water, food, ecological samples and in aerosols. The deterioration of the global epidemic situation caused by the spread of various strains of SARS-CoV-2 makes sensors based on CANARY technology especially relevant. To create a domestic analogue of such a biosensor, close cooperation with scientific institutions that specialize in molecular genetics and manufacturers of laboratory equipment is required.

DNA fragmentation of human spermatozoa: Simple assessment of single- and double-strand DNA breaks and their respective dynamic behavioral response.

Procedures to detect sperm DNA fragmentation (SDF), like the sperm chromatin dispersion (SCD) test, determine the "global" SDF without discriminating between spermatozoa with single-strand DNA breaks only (SDF-SSBs) and those containing double-strand DNA breaks (SDF-DSBs). (a) To validate a test to distinguish human spermatozoa with massive DSBs (DSB-SCD assay), (b) to study the baseline SDF-SSBs and SDF-DSBs, and (c) to assess their dynamics in vitro. (a) SDF-DSBs were determined by visualization of diffused DNA fragments from spermatozoa lysed under non-denaturing conditions. This was validated by in vitro incubation with DNase I and the comet assay. (b) Baseline SDF-DSBs and SDF-SSBs were determined in ejaculates from 95 males. (c) Their dynamic appearance was studied in samples untreated or exposed to hyperthermia, acidic pH, nitric oxide released by sodium nitroprusside (SNP), and the metabolic energy inhibitors 2-deoxy-D-glucose and antimycin A. (a) DNase I and comet assay experiments confirmed that the assay successfully determined SDF-DSBs. (b) The higher the SDF of the semen sample, the higher the frequency of SSBs, whereas DSBs behaved independently. Abnormal samples showed higher SDF than normozoospermic, the difference being only significant for SDF-SSBs. (c) During the first hours of incubation, the linear rate of increase in SDF-SSBs was 3.7 X higher than that of SDF-DSBs. All hazardous agents accelerated the SDF rate when compared to untreated spermatozoa, primarily being associated with SDF-SSBs. SNP treatment was the most damaging, rapidly inducing spermatozoa with SSBs which progressively evolved to DSBs. Remarkably, this phenomenon was also evidenced after acute SNP exposure, revealing cryptic sperm damage. The DSBs-SCD is an easy complement for SDF assessment. The dynamic study of SSBs and DSBs may improve the evaluation of sperm quality in clinical settings, particularly "unmasking" the presence of non-specific cryptic sperm damage that might otherwise go undetected.

Zeroth-order finite similitude and scaling of complex geometries in biomechanical experimentation.

Scaled experimentation provides an alternative approach to full-scale biomechanical (and biological) testing but is known to suffer from scale effects, where the underlying system behaviour changes with scale. This phenomenon is arguably the overriding principal obstacle to the many advantages that scaled experimentation provides. These include reduced costs, materials and time, along with the eschewal of ethical compliance concerns with the application of substitute artificial materials as opposed to the use of hazardous biological agents. This paper examines the role scale effects play in biomechanical experimentation involving strain measurement and introduces a formulation that overtly captures scale dependencies arising from geometrical change. The basic idea underpinning the new scaling approach is the concept of space scaling, where a biomechanical experiment is scaled by the metaphysical mechanism of space contraction. The scaling approach is verified and validated with finite-element (FE) models and actual physical-trial experimentation using digital image correlation software applied to synthetic composite bone. The experimental design aspect of the approach allows for the selection of three-dimensional printing materials for trial-space analysis in a complex pelvis geometry. This aspect takes advantage of recent advancements in additive manufacturing technologies with the objective of countering behavioural distorting scale effects. Analysis is carried out using a laser confocal microscope to compare the trial and physical space materials and subsequently measured using surface roughness parameters. FE models were constructed for the left hemipelvis and results show similar strain patterns (average percentage error less than 10%) for two of the three trial-space material combinations. A Bland-Altman statistical analysis shows a good agreement between the FE models and physical experimentation and a good agreement between the physical-trial experimentation, providing good supporting evidence of the applicability of the new scaling approach in a wider range of experiments.

Hollow Mesoporous Silica Sphere (HMSS) as a Recyclable Nano-catalyst in an Efficient One-Pot Multicomponent Synthesis of 2-Amino-3-Cyano-4H-Pyran Derivatives

Mesoporous material has a significant role in medicine, health care, environmental monitoring, sensing the hazardous agents, and fighting against viruses and bacteria. Nano-silica sphere is an important member of the mesoporous family that noticeably flourished in biology, health care, and other industrial applications. Efficient one-pot multicomponent syntheses of 2-amino-3-cyano-4H-pyran derivatives were carried out over readily available and simply synthesized recyclable Hollow Mesoporous Silica Sphere (HMSS). Comparable yields were encountered with better efficiency, lower cost, and shorter reaction time. Hence, superior catalytic activity, flexibility, ease of recovery, tuneable hole size, and high surface to volume ratio were the major characteristics of the catalyst which distinguish this protocol from previously reported ones. The catalyst was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) techniques, and nitrogen absorption and desorption (BET) analyses. The results showed that the synthesizing of HMSS catalysts under a mild and green condition in which comparable yields were encountered with better efficiency, lower cost, and shorter reaction with other major economic advantages.

Commercial infant cereals contain high concentrations of endotoxins and viable Bacillus spp.

BackgroundEndotoxin may cause inflammation and increased intestinal permeability in infants with immature immune systems and gut microbiota. This study analysed the presence of endotoxin together with other potentially hazardous agents in commercial infant cereals. MethodsFour porridges and six milk cereal drinks bought in Sweden were analysed for the presence of endotoxins using Endosafe MCS. The quantity of viable bacteria was determined using conventional culturing methods and the isolates were identified with Sanger sequencing. Enterotoxin producing genes were analysed through multiplex PCR and levels of mycotoxins were studied using uHPLC MS/MS. ResultsThe endotoxin concentration ranged from 1400 to 24200 EU/g powder. Viable bacteria were found in the products, indicating survivability of Bacillus spp in dry powders. No traces of mycotoxins were found. ConclusionThis study indicates that substantial concentrations of endotoxins are present in powdered infant cereal-based foods. Furthermore, the amount of living bacteria ingested with some of the products was high.

Revise of GBZ 2.1-2019 "occupational exposure limits for hazordous agents in the workplace part1: chemical hazardous agents"

Revise of GBZ 2.1-2019 "occupational exposure limits for hazordous agents in the workplace part1: chemical hazardous agents"

(Keynote) Terahertz Nanoplasmonics Technology: Physics, Applications, and Commercialization

The minimum feature sizes of the Si VLSI reduced to 7 nm in 2017 with the 5 nm Si VLSI reported at IEDM 2019 and 3 nm Si VLSI technology on the roadmap for 2021. These transistors operate in the regime when the electron mean free path for collisions with impurities or lattice vibrations exceeds the device dimension. One new feature of this mode of transport is “ballistic mobility” replacing the conventional mobility and being proportional to the channel length. At high frequencies, the electron inertia in short channel devices plays a dominant role and the waves of the electron density (plasma waves) enable the device response well into the terahertz (THz) range of frequencies. Excitation and rectification of the plasma waves enables numerous application in terahertz sensing and communications. Terahertz sensing enables detection of biological and chemical hazardous agents, cancer detection, detection of mines and explosives, provides security in buildings, airports, and other public spaces, and widely used for industry quality control and radio astronomy applications. A new emerging application is for cyber hardware security to distinguish between faked and genuine VLSI chips and predict the VLSI reliability. THz communications, extensively explored since the beginning of the 21-st century, will enable very high data rates (over 430 GPS demonstrated for the W-band) for applications such as driverless cars, autonomous tactical networking with ground and aerial vehicles, and 4K video and cloud storage applications. THz signals can penetrate through fog and dust. The available bandwidth at THz frequencies, makes them uniquely suited for Wireless Local Area Networks (WLAN) and Wireless Personal Area Networks (WPAN). THz sources and detectors can produce tight beam widths and support low power directional networking. The 200 to 300 GHz band is proposed for the next generation Wi-Fi (beyond 5G) that could be implemented using deep submicron silicon. GaN, p-diamond, and graphene based Terahertz FETs – TeraFETs - will compete with Si for THz applications promising further improvements in THz detectivity and generated THz power. There is, however, a large gap between the advanced experimental and theoretical THz electronics research and currently deployed THz technology. I will discuss the problems facing the THz plasmonic nanoplasmonics technology commercialization and projections for bridging the famous THz gap. Figure 1

Green synthesis of cerium oxide nanoparticles: characterization, parameters optimization and investigation of photocatalytic application

In the present work, cerium oxide nanoparticles were synthesized using a very simple and green method. Egg white was used as a stabilizing agent in order to size and morphology control. The nanoparticles were obtained without any toxic and hazardous chemical agent at room temperature. The effective parameters on nanoparticles synthesis such as pH, amount of stabilizing agent and calcination temperature were optimized. The size and morphology of prepared nanoparticles were investigated and determined with XRD and FESEM. In optimum conditions, nanoparticles were synthesized with about 9 nm in size. The ability of the synthesized green oxide cerium nanoparticles was investigated as photocatalyst for the degradation of two dyes of malachite green and methyl orange. The experiments were carried out in visible light and ambient temperature and effective parameters on degradation process such as dye solution, pH, photocatalyst amount and process time were optimized. The obtained results show that the dye degradation happens as well in short time.

Thermal reduction of sulfur-containing MAX phase for MXene production

Two-dimensional (2D) MXene, as an important member of the emerging 2D nanomaterials, has received much attention in recent years, especially in energy-related fields. Unfortunately, the controllable synthesis of high-purity MXenes in a scalable way is still a challenge, due to the usual utilization of hazardous etching agents. It is highly desired that a simple, controllable, and effective approach is available for producing MXene in a green manner. In this work, an innovative thermal reduction strategy is proposed for the fabrication of MXenes from the corresponding sulfur-containing MAX phases, in which the weakly bonded S atoms react with hydrogen to form a volatile gas and leave 2D graphene-like Ti2C nanosheets. As a promising anode material for electrochemical Li+ ion storage, the resulting MXene demonstrated satisfying initial discharge capacities of ~200 mAh g−1. Furthermore, the capacity remained at ~70 mAh g−1 over 130 cycles even at a high rate of 2.0 A g−1, indicating a good rate capability and cycling stability. This work thus offers a novel approach for MXene fabrication and enriches MXene-based electrode materials for energy devices.

γ-Nanofluid Thermal Transport between Parallel Plates Suspended by Micro-Cantilever Sensor by Incorporating the Effective Prandtl Model: Applications to Biological and Medical Sciences

The flow of nanofluid between infinite parallel plates suspended by micro-cantilever sensors is significant. The analysis of such flows is a rich research area due to the variety of applications it has in chemical, biological and medical sciences. Micro-cantilever sensors play a significant role in accurately sensing different diseases, and they can be used to detect many hazardous and bio-warfare agents. Therefore, flow water and ethylene glycol (EG) composed by γ-nanoparticles is used. Firstly, the governing nanofluid model is transformed into two self-similar nanofluid models on the basis of their effective models. Then, a numerical method is adopted for solution purposes, and both the nanofluid models are solved. To enhance the heat transfer characteristics of the models, the effective Prandtl model is ingrained in the energy equation. The velocity F’(η) decreases with respect to the suction of the fluid, because more fluid particles drags on the surface for suction, leading to an abrupt decrement in F’(η). The velocity F’(η) increases for injection of the fluid from the upper end, and therefore the momentum boundary layer region is prolonged. A high volume fraction factor is responsible for the denser characteristics of the nanofluids, due to which the fluids become more viscous, and the velocity F’(η) drops abruptly, with the magnetic parameters favoring velocity F’(η). An increase in temperature of Al2O3-H2O and γAl2O3-C2H6O2 nanofluids was reported at higher fraction factors with permeable parameter effects. Finally, a comparative analysis is presented by restricting the flow parameters, which shows the reliability of the study.

Assessment of the prevalence of Respiratory Symptoms among the Workers of Automobile Industry

Objective: To assess the prevalence of respiratory system symptoms among the workers of automobile industry who are frequently exposed to hazardous chemical agent and dust. Study Design: Cross-sectional observational study. Place and Duration of Study: Nishtar Hospital Multan, Bahawal Victoria hospital Bahawalpur. from August 2018 to March 2019. Methodology: Sixty eight participants of which 34 were exposed and 34 were non-exposed workers of an automobile factory were selected. Age, BMI, smoking history, lung functions including FEV 1 , FVC, FEV1/FVC, PEF, PEF 25-75 and VC before and after the work shift, symptoms including dry throat, runny nose, headache, fatigue, cough, phlegm, dyspnea, and wheeze; and chest tightness were compared between the cases and controls. Independent t-test, paired t-test and chi-square tests were applied. Data was analyzed with SPSS v.23.0 after considering p<0.05 statistically significant. Results: FEV 1 , PEF, and VC were significantly decreased in the exposed workers as compared those who were not exposed (p-value <0.001, <0.001 and 0.001, respectively). The decrease in FVC and FEV1/FVC and FEV1/VC ratio was also significant (p-value 0.011, 0.002 and 0.048, respectively). Dry throat, runny nose and fatigue were significantly more in cases (p-value 0.022, 0.016 and 0.018, respectively). Cough, phlegm, wheeze, and dyspnea; and chest tightness were more prevalent in the cases (p-value 0.015, <0.001, 0.001, <0.001 and 0.001, respectively). Conclusion: Decline in lung functions and prevalence of respiratory symptoms were significant in the workers exposed to dust and BTEX warranting the performance of lung function tests before and after the employment for the identification of the sensitive personnel. Keywords: automobile factories, respiratory symptoms, prevalence. DOI: 10.7176/JMPB/65-07 Publication date: April 30 th 2020