scholarly journals Macroscopic Observation of Soil Nitrification Kinetics Impacted by Copper Nanoparticles: Implications for Micronutrient Nanofertilizer

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 927 ◽  
Author(s):  
Allison VandeVoort ◽  
Yuji Arai
Keyword(s):  
Slow Release ◽  
Average Rate ◽  
Copper Toxicity ◽  
Surface Oxidation ◽  
Reaction Products ◽  
Edge Structure ◽  
Soil Nitrification ◽  
Soil Systems ◽  
Nitrification Kinetics ◽  
The Impact

The potential agricultural use of metal nanoparticles (NPs) for slow-release micronutrient fertilizers is beginning to be investigated by both industry and regulatory agencies. However, the impact of such NPs on soil biogeochemical cycles is not clearly understood. In this study, the impact of commercially-available copper NPs on soil nitrification kinetics was investigated via batch experiments. The X-ray absorption near edge structure spectroscopy analysis showed that the NPs readily oxidized to Cu(II) and were strongly retained in soils with minimum dissolution (<1% of total mass). The Cu2+ (aq) at 1 mg/L showed a beneficial effect on the nitrification similar to the control: an approximately 9% increase in the average rate of nitrification kinetics (Vmax). However Vmax was negatively impacted by ionic Cu at 10 to 100 mg/L and CuNP at 1 to 100 mg/L. The copper toxicity of soil nitrifiers seems to be critical in the soil nitrification processes. In the CuNP treatment, the suppressed nitrification kinetics was observed at 1 to 100 mg/kg and the effect was concentration dependent at ≥10 mg/L. The reaction products as the results of surface oxidation such as the release of ionic Cu seem to play an important role in suppressing the nitrification process. Considering the potential use of copper NPs as a slow-release micronutrient fertilizer, further studies are needed in heterogeneous soil systems.

scholarly journals Macroscopic Observation of Soil Nitrification Kinetics Impacted by Copper Nanoparticles: Implications for Nanotechnology for Micronutrient Fertilizer

2018 ◽  
Author(s):  
Yuji Arai ◽  
Allison vandervoort
Keyword(s):  
Slow Release ◽  
Surface Oxidation ◽  
Reaction Products ◽  
Edge Structure ◽  
Soil Nitrification ◽  
Soil Systems ◽  
Nitrification Kinetics ◽  
Macroscopic Observation ◽  
The Impact ◽  
Micronutrient Fertilizer

The potential agricultural use of metal nanoparticles (NPs) for slow-release micronutrient fertilizers is beginning to be investigated by both industry and regulatory agencies. However, the impact of such NPs on soil biogeochemical cycles is not clearly understood. In this study, impacts of a commercially-available copper NPs on the soil nitrification kinetics was investigated via batch experiments. The X-ray absorption near edge structure spectroscopy analysis showed that the NPs readily oxidized to Cu(II) and strongly retained in soils with minimum dissolution (&lt;1% of total mass). The Cu2+ (aq) at 1mg/L showed the beneficial effect on the nitrification, an increase in the rate of nitrification kinetics (Vmax). However Vmax was negatively impacted by ionic Cu at 10-100mg/L and CuNP at 1-100 mg/L. The trace metal toxicity of soil nitrifiers seems to be critical in the soil nitrification processes. Among CuNPs, the suppressed nitrification kinetics was concentration dependent at &gt;10mg/L. The reaction products of surface oxidation such as the release of ionic Cu seem to play an important role in suppressing the nitrification process. Considering the potential use of copper NPs as a slow-release micronutrient fertilizer, further studies are needed in heterogeneous soil systems.

scholarly journals Incidence and causes of lower-limb amputations in the city of Ribeirão Preto from 1985 to 2008: evaluation of the medical records from 3,274 cases

2016 ◽  
Vol 19 (2) ◽  
pp. 317-325 ◽  
Author(s):  
Bruna Maria Bueno Barbosa ◽  
Rosane Aparecida Monteiro ◽  
Lucas Françolin Sparano ◽  
Rodolfo Fabiano Niz Bareiro ◽  
Afonso Dinis Costa Passos ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Lower Limb ◽  
Population Aging ◽  
Average Rate ◽  
Control Program ◽  
Diabetes Control ◽  
Ischemic Complications ◽  
The Impact ◽  
The City ◽  
Alcohol Laws

ABSTRACT: Objective: It was to identify trends of traumatic and non-traumatic causes of lower limb amputations, as well as the role played by population aging, traffic violence increase, public health policy of diabetes control program and drivers anti-alcohol laws on these amputations. Method: Hospitalization data recorded in the discharge forms of 32 hospitals located in the region of Ribeirão Preto, Brazil, from 1985 to 2008 were analyzed. Result: A total of 3,274 lower-limb amputations were analyzed, of which 95.2% were related to non-traumatic causes, mainly infectious and ischemic complications of diabetes mellitus. Cancer (2.8%) and congenital (1.3%) causes were included in this group. Only 4.8% were related to traumatic causes. Traumatic amputation average rate was 1.5 amputations in 100,000 habitants with a slight tendency of increase in the last 5 years. Non-traumatic causes showed an average rate of 30.0 amputations for 100,000 habitants and remained relatively constant during the whole period. Non-traumatic were much more predominant in patients older than 60 years and traumatic amputations occurred more frequently in patients younger than 39 years. Conclusion: The overall rates of amputation and the rates of traumatic and non-traumatic amputations remained nearly constant during the study period. The impact of diabetes control policies and the introduction of traffic safety laws could not be identified on the amputation rates.

scholarly journals ARUS KAS, CASH HOLDING, KENDALA PENDANAAN DAN INVESTASI DI INDONESIA

AdBispreneur ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 169
Author(s):  
Risal Rinofah
Keyword(s):  
Cash Flow ◽  
Financial Constraints ◽  
Average Rate ◽  
Cash Flows ◽  
Cash Holding ◽  
Investment Level ◽  
Show Evidence ◽  
The Impact ◽  
A Company ◽  
Positive Effect

ABSTRACTThis study aims to detect Cash Flow, Cash Holding and Financial Constraints effect on investment decisions of companies in Indonesia. Some of the previous studies outside Indonesia show evidence of the impact of cash flows and financial constraints on it’s investment level.Using Multiple Regression and Logistic Regression model, on five years data observation shows that cash flow and cash holding have a positive effect on investment level. Interaction test shows the effect of cash flow on investment in financially constrained different from financially unconstrained companies. In other words, the average rate of investment changes caused by the level of cash flow is the same for both companies. While the effect of cash holding on investment, no different in the company that financially constraint and financially unconstraint company.The contribution of this research is to provide insight to the parties related to the importance of cash flow and cash holding to the investment of a company. Based on the results it can be concluded that companies that have cash flow and high cash holding have greater investment opportunities, especially in companies that have problems in finding sources of funding.   ABSTRAKPenelitian ini bertujuan untuk mendeteksi pengaruh Arus Kas, Cash Holding dan Kendala Finansial terhadap keputusan investasi perusahaan di Indonesia. Beberapa penelitian sebelumnya di luar Indonesia menunjukkan bukti ada pengaruh Arus Kas dan Kendala Keuangan pada tingkat investasi.Dengan menggunakan model Regresi Berganda dan Regresi Logistik, pada pengamatan data selama lima tahun menunjukkan bahwa Arus Kas dan Cash Holding berpengaruh positif terhadap tingkat investasi. Uji interaksi menunjukkan pengaruh Arus Kas terhadap investasi pada perusahaan yang mengalami kendala pendanaan berbeda dengan perusahaan yang tidak mengalami kendala pendanaan. Dengan kata lain, tingkat rata-rata perubahan investasi yang disebabkan oleh tingkat arus kas adalah sama untuk kedua perusahaan. Sedangkan pengaruh Cash Holding terhadap investasi, tidak berbeda pada perusahaan yang mengalami kendala pendanaan maupun tidak.Kontribusi dari penelitian ini adalah untuk memberikan wawasan kepada pihak-pihak yang terkait dengan pentingnya arus kas dan Cash Holding untuk investasi perusahaan. Berdasarkan hasil tersebut dapat disimpulkan bahwa perusahaan yang memiliki Arus Kas dan Cash Holding yang tinggi memiliki peluang investasi yang lebih besar, terutama pada perusahaan yang memiliki masalah dalam mencari sumber pendanaan. 

scholarly journals Investigating the Impact of Asymptomatic Carriers on COVID-19 Transmission

2020 ◽  
Author(s):  
Jacob B. Aguilar ◽  
Jeremy Samuel Faust ◽  
Lauren M. Westafer ◽  
Juan B. Gutierrez
Keyword(s):  
Disease Surveillance ◽  
Reproduction Number ◽  
Clinical Symptoms ◽  
Communicable Disease ◽  
Average Rate ◽  
Point Estimate ◽  
Surveillance Systems ◽  
Average Case ◽  
Asymptomatic Carriers ◽  
The Impact

Coronavirus disease 2019 (COVID-19) is a novel human respiratory disease caused by the SARS-CoV-2 virus. Asymptomatic carriers of the virus display no clinical symptoms but are known to be contagious. Recent evidence reveals that this sub-population, as well as persons with mild disease, are a major contributor in the propagation of COVID-19. The asymptomatic sub-population frequently escapes detection by public health surveillance systems. Because of this, the currently accepted estimates of the basic reproduction number (ℛ0) of the disease are inaccurate. It is unlikely that a pathogen can blanket the planet in three months with an ℛ0 in the vicinity of 3, as reported in the literature (1–6). In this manuscript, we present a mathematical model taking into account asymptomatic carriers. Our results indicate that an initial value of the effective reproduction number could range from 5.5 to 25.4, with a point estimate of 15.4, assuming mean parameters. The first three weeks of the model exhibit exponential growth, which is in agreement with average case data collected from thirteen countries with universal health care and robust communicable disease surveillance systems; the average rate of growth in the number of reported cases is 23.3% per day during this period.

Ground Rubber Tire / Thermoplastic Composites: Effect of Different Ground Rubber Tires

1993 ◽  
Vol 66 (4) ◽  
pp. 664-677 ◽  
Author(s):  
P. Rajalingam ◽  
J. Sharpe ◽  
W. E. Baker
Keyword(s):  
Particle Size ◽  
Impact Energy ◽  
Surface Oxidation ◽  
Surface Concentration ◽  
Thermoplastic Composites ◽  
Beam Radiation ◽  
Rubber Tire ◽  
Ground Rubber ◽  
Surface Modification Techniques ◽  
The Impact

Abstract Thermoplastic composites containing different Ground Rubber Tire (GRT) materials, Linear Low Density Polyethylene (LLDPE) and, in some case, a coupling agent (IB‘E’, an ethylene glycidyl methacrylate copolymer) were prepared by melt blending. The impact energies of all the thermoplastic composites (normally containing 40 wt % GRT) were evaluated using an instrumented impact tester. The effects of the GRT particle-size, particle size distribution and shape, the mode of grinding, and the oxygen surface concentration were analyzed. The wet-ambient-ground GRT based composites show higher surface oxidation and give better impact energy than cryo-ground and normal air-ground GRT based composites. Smaller GRT particle size results in a small increase in the impact property of the composite and a greater influence on the melt processability of the composites. Of the different GRT surface modification techniques studied for improved composite interfacial adhesion and impact properties the composites from electron beam radiation treated GRT yield higher increases in impact energy in comparison to corona and plasma treated GRT based composites.

Biodegradability of single-use polypropylene-based face masks, littered during the COVID-19 pandemic – a first approach 

2021 ◽  
Author(s):  
Heike Knicker ◽  
Marta Velasco-Molina
Keyword(s):  
Soil Microbes ◽  
Degradation Mechanism ◽  
Chemical Processes ◽  
Natural Soil ◽  
Environmental Consequences ◽  
Soil Systems ◽  
Single Use ◽  
Physical And Chemical ◽  
The Impact ◽  
Water Holding

&lt;p&gt;The COVID-19 pandemic caused a massive use of disposable sanitary face masks. Based on data provided by Prata et al. (2020), we estimated that if only 0.1% of those masks are improperly discarded and enter the soil, approximately 361&lt;sup&gt;&lt;/sup&gt;t of polypropylene (PP) will be monthly added to the soil, threatening the ecological balance of terrestrial systems, the health of wild animals and even humans. For a first evaluation of the environmental consequences of the mask littering during COVID-19, we compared the microbial degradability of 10 x 10 mm cuts of the single masks layers and the complete mask blended with topsoil from a Cambisol of the Sierra de Aznalc&amp;#243;llar, Southern Spain with natural soil organic matter (SOM) by measuring the CO&lt;sub&gt;2&lt;/sub&gt; release during a three-month decomposition experiment performed with a soil moisture of 75% of its maximal water holding capacity and at 25&amp;#176;C. In order to focus on biodegradation and to avoid abiotic impact of physical and chemical processes, the masks were not pretreated or exposed to UV-irradiation or natural daylight prior to decomposition. In addition, the incubation occurred in the dark. We identified an easily decomposable fraction with a mean residence time (MRT&lt;sub&gt;fast&lt;/sub&gt;) of 2 to 3 days, releasing approximately 3 to 5% of the total mask carbon as CO&lt;sub&gt;2&lt;/sub&gt;. Solid-state nuclear magnetic resonance (NMR) spectroscopy confirmed that all three layers of the mask were composed of PP without contributions of more than 2-3% of other additives. Microbial degradation resulted in a cut-off of terminal PP units as a main degradation mechanism. Assuming again that about 0.1% of the masks used during the COVID-19 crises may enter soil systems, we estimated that this fast pool may cause an additional CO&lt;sub&gt;2&lt;/sub&gt; emission of 41 to 68 t year&lt;sup&gt;-1&lt;/sup&gt;. This corresponds to the globally averaged annual CO&lt;sub&gt;2&lt;/sub&gt;-footprint of 10 to 17 persons (4 t year&lt;sup&gt;-1&lt;/sup&gt; person&lt;sup&gt;-1&lt;/sup&gt;).&amp;#160; The slow turning fraction was mineralized with a rate constant of 0.05 to 0.14 year&lt;sup&gt;-1&lt;/sup&gt; corresponding to a MRT&lt;sub&gt;slow&lt;/sub&gt; between 7 and 18 years. This is two to four times longer than that determined for the SOM pure reference soil but still lies in the range reported for humified SOM derived from other topsoils of the Sierra de Aznalc&amp;#243;llar. Our results allow us to confirm our hypothesis that in soil, microbes exist that can decompose PP, although their nature still has to be revealed in future attempts. Studies investigating the impact of pre-exposure to daylight and moisture on their degradability in soils are in process.&lt;/p&gt;&lt;p&gt;Prata, J.C., Silva, A.L.P., Walker, T.R., Duarte, A.C., Rocha-Santos, T., 2020. COVID-19 Pandemic Repercussions on the Use and Management of Plastics. Environ. Sci. Technol. 54, 7760&amp;#8211;7765. https://doi.org/10.1021/acs.est.0c02178&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Postoperative use of slow-release opioids: The impact of the Australian and New Zealand College of Anaesthetists/Faculty of Pain Medicine position statement on clinical practice

2020 ◽  
Vol 48 (6) ◽  
pp. 444-453
Author(s):  
Adeline CH Tan ◽  
Bernadette A Bugeja ◽  
David A Begley ◽  
Jennifer A Stevens ◽  
Kok-Eng Khor ◽  
...  
Keyword(s):  
Clinical Practice ◽  
New Zealand ◽  
Odds Ratio ◽  
Slow Release ◽  
Immediate Release ◽  
Prescribing Patterns ◽  
Dose Titration ◽  
Pain Medicine ◽  
Zealand College ◽  
The Impact

Dose titration with immediate-release opioids is currently recommended for acute pain. The Australian and New Zealand College of Anaesthetists and the Faculty of Pain Medicine released a statement in March 2018 supporting their use in the treatment of opioid-naïve patients; however, the impact of this statement on clinical practice is currently unknown. This retrospective cohort study was conducted to compare opioid prescribing patterns before and after the release of the recommendations. Data were collected on 184 patients (2017, n = 78; 2018, n = 106) admitted to the Prince of Wales Hospital in November 2017 and 2018, which consisted of demographic data, opioid prescriptions and discharge opioid information. The main outcome is the number of prescriptions of slow-release opioids in 2017 versus 2018 after the recommendations were published. Confounding factors were accounted for using logistic and multiple regression as appropriate. There was a 29% decrease in slow-release opioid prescriptions during hospitalisation ( n = 31, 40% versus n = 12, 11%; P < 0.001) and 17% decrease at discharge ( n = 20, 26% versus n = 9, 9%; P = 0.02) post-publication. After adjusting for confounders, the odds of slow-release opioids being prescribed postoperatively and at discharge reduced by 86% and 88%, respectively (postoperative period: odds ratio 0.14, P < 0.05; discharge: odds ratio 0.12, P < 0.05). In addition, orthopaedic patients were more likely to receive slow-release opioids, consistent with existing literature. As the use of slow-release opioids has been associated with increased harm and protracted opioid use compared to immediate-release opioids, it is hoped that wider dissemination of these recommendations and a change in prescribing practice can be a step towards overcoming the opioid crisis.

Application of CFD-DSMC coupling method in micro-scale gas flow and combustion

2020 ◽  
Vol 34 (27) ◽  
pp. 2050301
Author(s):  
Shaoyi Suo ◽  
Linsong Jiang ◽  
Maozhao Xie
Keyword(s):  
Boundary Layer ◽  
Chemical Reaction ◽  
Wall Temperature ◽  
Slip Velocity ◽  
Gas Flow ◽  
Wall Slip ◽  
Reaction Products ◽  
Microscopic Method ◽  
Flow Heat ◽  
The Impact

The reversible elementary reaction mechanism of six components and seven steps of H2/O2 are applied by using a CFD-DSMC coupling iteration method to study the impact of boundary on flow, heat transfer and chemical reaction in a microtube. The microtube consists of a converging section and a straight section, which represents the gap on the contact surface of the pellets in porous media. It shows that after coupling, with the designed conditions in this paper, the influence of wall temperature is more obvious than that of wall slip velocity on the coupling results from the analysis of chemical reaction, yet the velocity field in the boundary layer is more affected by the wall slip velocity. In addition, the velocity in the central region of the flow decreases while the concentration of reaction products increases after coupling, due to the increasing of the velocity in the boundary layer and the influence of wall temperature, respectively. By the coupling of CFD-DSMC methods, more details and influence of the boundary can be considered, and the computational efficiency is higher than that of the single microscopic method.

The effects of uncertain forest conservation benefits on long-run deforestation in the Brazilian Amazon

2018 ◽  
Vol 23 (4) ◽  
pp. 413-433 ◽  
Author(s):  
Luca Di Corato ◽  
Michele Moretto ◽  
Sergio Vergalli
Keyword(s):  
High Speed ◽  
Forest Conservation ◽  
Average Rate ◽  
Land Development ◽  
Brazilian Amazon ◽  
Forest Conversion ◽  
Conservation Policies ◽  
Expected Time ◽  
Long Run ◽  
The Impact

AbstractDeforestation results from the trade-off between benefits from forest conservation and economic profits associated with land development. However, as net gains are often uncertain, irreversible land development may later be regretted. To better inform conservation policies, we use a real options framework to model irreversible forest conversion under uncertain conservation benefits and determine the associated optimal long-run average rate of deforestation. We then analyze the impact of the demand for agricultural products on the rate of deforestation in the Brazilian Amazon. In a scenario analysis for the nine states of the Brazilian Amazon, we calculate: (i) the expected time for exhaustion of the current forest stock; and (ii) the potential forest coverage for the next 20, 100 and 200 years. Our results suggest that if forest benefits grow over time at a sufficiently high speed, they may significantly slow down deforestation. In contrast, the higher their volatility, the faster deforestation proceeds.

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