Minimum quantity lubrication in grinding: effects of abrasive and coolant–lubricant types

This research has been conducted to study the influence of the abrasive and coolant–lubricant types on the minimum quantity lubrication (MQL) grinding performance. One type of CBN and three types of conventional wheels (corundum) have been tested. The tests have been performed in presence of fluid, air jet and eleven types of coolant–lubricants, as well as, in dry condition. The results indicate that the finest surface quality and lower grinding forces could be obtained while grinding with CBN wheel. In case of conventional wheels, the coarser and high porosity wheels induce much proper grinding results. Furthermore, grinding when utilizing MQL with oil results in higher grinding performance.     

Removing ammonia from air with a constant pH,slightly acidic water spray wet scrubber using recycled scrubbing solution

Slightly acidic solutions are a practical means of removing ammonia from air Scrubbed NH₃ accumulates in solution as NH₄⁺ and should be an excellent fertilizer Increased air velocity decreased NH₃ removal and increased NH₄⁺ collection Previous research on wet scrubbers has only studied highly acidic scrubbing solutions because of their high ammonia capture efficiencies; however, the high acidity created practical problems. Lower acidity solutions would reduce corrosion, maintenance, and cost; however, designers may need to use strategies for increasing scrubber effectiveness, such as using lower air velocities. The objective of this study was to determine if a spray scrubber with slightly acidic and higher pH scrubbing solution (pH from 2 to 8) could effectively remove NH₃ from NH₃ laden air (such as animal building exhaust air), and also collect this valuable resource for later use as a fertilizer. A bench-scale spray wet scrubber treated 20 ppmv NH₃/air mixture in a countercurrent contact chamber. First, the solution pH was varied from 2 to 8 while maintaining constant air velocity at 1.3 m·s⁻¹. Next, air velocity was increased (2 and 3 m·s⁻¹) while solution pH remained constant at pH6. At 1.3 m·s⁻¹, NH₃ removal efficiencies ranged between 49.0% (pH8) and 84.3% (pH2). This study has shown that slightly acidic scrubbing solutions are a practical means of removing ammonia from air especially if the scrubber is designed to increase collisions between solution droplets and NH₃ molecules. The NH₃ removed from the air was held in solution as NH₄⁺ and accumulates over time so the solution should be an excellent fertilizer.     

Economic evaluation of measles catch-up and follow-up campaigns in Afghanistan in 2002 and 2003

This paper assesses the cost-effectiveness of, and the return on the investment in, the 2002 catch-up and the 2003 follow-up measles campaigns in Afghanistan from the perspective of the donor. The catch-up campaign targeted nearly 12 million children aged between six months and 12 years, while the follow-up campaign targeted over five million children aged between 9 and 59 months. Both campaigns successfully vaccinated approximately 96 per cent of the respective target populations, and are expected to avert an estimated 301,000 measles deaths over the next 10 years. The average cost per dose of measles vaccine delivered was USD 0.40. The cost per death prevented is USD 23.6, assuming a case fatality rate of 10 per cent and a discount rate of three per cent. With more than 42,000 measles deaths avoided for every one million US dollars spent, the campaigns are an excellent public health investment for precluding childhood mortality in a country affected by a complex emergency.     

Economic complexity,ICT, biomass energy consumption,and environmental degradation: evidence from Iran

Economic complexity, biomass energy consumption, and information communication technology (ICT) have diverse impacts on energy consumption and carbon dioxide (CO₂) emissions. Nevertheless, analysis of these variable effects is not addressed in the previous literature; the antiqueness of this article is stuffing this gap. This study assessed the relationship between gross domestic product (GDP) per capita, biomass consumption, economic complexity index (ECI), ICT, and CO₂ emissions in Iran in 1994–2018. The autoregressive distributed lag (ARDL) model and the quantile regression (QR) econometric technique were used to investigate the factors affecting CO₂ emissions in the tails of the conditional distribution. The share of each influential factor was predicted through the variance decomposition analysis (VD) for the next 10 years. The empirical results showed a long-run relationship between the variables. So, the variables of biomass consumption, ECI, and ICT improve the quality of the environment in Iran by reducing CO₂ emissions, and the per capita GDP variable increases CO₂ emissions. Results suggest no evidence indicating the presence of environmental Kuznets curve (EKC); however, QR demonstrated the existence of EKCs in the lower quantiles of the conditional distribution. The ECI will have the most share to change the CO₂ emissions in the future. The income threshold should be determined at the turning point of the EKC to increase economic development. Moreover, investing in increasing biomass consumption is vital. Policymakers also need to consider strict added value for the export of products.

     

Energy-efficient removal of carbamazepine in solution by electrocoagulation-electrofenton using a novel P-rGO cathode

In this study,carbamazepine(CBZ) decay in solution has been studied by coupling electrocoagulation with electro-Fenton(EC-EF) with a novel P-rGO/carbon felt(CF) cathode,aiming to accelerate the in-situ generation of ·OH,instead of adding Fe²⁺ and H₂ O₂.Firstly,the fabricated P-rGO and its derived cathode were characterized by XRD,SEM,AFM,XPS and electrochemical test(EIS,CV and LSV).Secondly,it was confirmed that the performance in removal efficiency and electric ...     

Investigation of simultaneous multiple UV filters degradation efficiency of plasmonic Ag@AgCl photocatalyst in the aquatic environment under sunlight irradiation

Environmental Science and Pollution Research - UV filters as an important class of emerging organic pollutants are continuously released into and transported between the aquatic environments. So,...     

Characteristics of wood–fiber plastic composites made of recycled materials

This study investigates the feasibility of using recycled high density polyethylene (rHDPE), polypropylene (rPP) and old newspaper (rONP) fiber to manufacture experimental composite panels. The panels were made through air-forming and hot press. The effects of the fiber and coupling agent concentration on tensile, flexural, internal bond properties and water absorption and thickness swelling of wood–fiber plastic composites were studied. The use of maleated polypropylene as coupling agent improved the compatibility between the fiber and both plastic matrices and mechanical properties of the resultant composites compared well with those of non-coupled ones. Based on the findings in this work, it appears that recycled materials can be used to manufacture value-added panels without having any significant adverse influence on board properties. It was also found that composites with rHDPE provided moderately superior properties, compared with rPP samples.     

Classification of the Caspian Sea coastal waters based on trophic index and numerical analysis

In order to characterize the trophic state of the southern coastal waters of the Caspian Sea, trophic index (TRIX) as well as numerical analysis using cluster and discriminant analysis were employed in this study. Chemical and biological parameters (NO₃, NO₂, NH₄, PT, DO, and Chla) used in this study were collected seasonally from summer 1999 to spring 2000. A new trophic index developed by modification of TRIX indicated mesotrophic to eutrophic conditions for the Caspian Sea. Numerical analysis revealed three groups of the study area and it was found that the used methods are in good agreement. Both of them predicted poor to moderate conditions in the western part of the study area and the numerical classification predicted trophic conditions in the study area. However, TRIX was found to be a more accurate and suitable method. It performs more conservatively than the numerical classification and characterized lower classes of water quality for the stations in central and eastern parts of the study area.     

Investigation of the Thermosensitive Nanosphere Polymer in Removing Organophosphorus Pesticides from Water and Its Isotherm Study (Case Study: Diazinon)

In this research, a novel thermosensitive nanosphere polymer (TNP) was synthesized by copolymerization of N-isopropylacrylamide with 3-allyloxy-1,2-propanediol for the removal of diazinon from water. The characterization of the synthesized adsorbent has been performed by Fourier transform infrared spectrometer, scanning electron microscopy and elemental analysis. Batch adsorption method was performed to investigate the influences of various parameters like pH, temperature and contact time on the adsorption of diazinon. The equilibrium adsorption data of diazinon by TNP was studied by Langmuir, Freundlich, Temkin and Redlich–Peterson model. According to equilibrium adsorption results, the Langmuir, Freundlich and Temkin constants were evaluated to be 0.912 (L/mg), 7.916 (mg/g) (L/mg)^1/n and 2.494 respectively at pH 7 and room temperature. Based on Redlich–Peterson model analysis, the equilibrium data for the adsorption of diazinon was conformed well to the Langmuir isotherm model. This method was successfully applied for removal of diazinon from environmental samples. Moreover, in reusing of TNP, the sorption capacity was maintained without any significant change after 10 cycles of sorption–desorption process.     

Air pollution perception in ten countries during the COVID-19 pandemic

As largely documented in the literature, the stark restrictions enforced worldwide in 2020 to curb the COVID-19 pandemic also curtailed the production of air pollutants to some extent. This study investigates the perception of the air pollution as assessed by individuals located in ten countries: Australia, Brazil, China, Ghana, India, Iran, Italy, Norway, South Africa and the USA. The perceptions towards air quality were evaluated by employing an online survey administered in May 2020. Participants (N = 9394) in the ten countries expressed their opinions according to a Likert-scale response. A reduction in pollutant concentration was clearly perceived, albeit to a different extent, by all populations. The survey participants located in India and Italy perceived the largest drop in the air pollution concentration; conversely, the smallest variation was perceived among Chinese and Norwegian respondents. Among all the demographic indicators considered, only gender proved to be statistically significant.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01574-2.