The half-lives of biological activity of some pesticides in water

In the absence of analytical methods, the half-lives of biological activity of pesticides can be estimated by bioassays. To determine the half-lives of biological acivity of pesticides to fish, static bioassays were conducted in the laboratory with ten different formulations of pesticides using Labeo rohita as a bio-indicator. The half-lives of biological activity for ten different pesticides in soft water at pH 7.5 and 27°C, ranged from 4.6 days to 11.8 days. The half-life of biological activity of Sumithion 50% EC was only 4.6 days. In contrast, Dimecron 50% EC degraded very slowly and its half-life of biological activity on L. rohita was about 11.8 days. Sumithion 50% EC, Padan 50% SP, EPN 45% EC, Diazinon 40% EC and Diazinon 10 G degraded in less than five to seven days indicating that these pesticides are desirable for rice-fish culture. Contamination by pesticides with long-term residual toxicity in waters may eventually cause high levels of fish mortality

A Combined FEM-CFD Methodology to Study and Optimize Acoustic Properties of Marine Exhaust Lines

Lo sviluppo di sistemi di abbattimento compatti in grado di ridurre sia NOx che SOx è di forte interesse, per la difficoltà di combinare su una nave sia sistemi di riduzione catalitica selettiva che tecnologie di scrubber. Quindi, la ricerca sviluppata in questa tesi nasce dalla necessità di integrazione del sistema lungo la linea di scarico per risparmiare spazio e dalla necessità di disporre di un modello numerico adeguato per simulare le proprietà acustiche dei sistemi di depurazione dei gas di scarico per la loro ottimizzazione. L'obiettivo di questa tesi è sviluppare una metodologia numerica efficiente dal punto di vista computazionale che utilizzi una combinazione di simulazioni CFD e FEM, per consentire lo studio e l'ottimizzazione delle proprietà acustiche dei componenti della linea di scarico, rispettando i limiti imposti sia ai parametri geometrici che alle caratteristiche del flusso dalle reazioni chimiche necessarie per soddisfare le normative NOx e SOx. Sono stati eseguiti alcuni studi preliminari per ottimizzare l’onere computazionale delle simulazioni numeriche. Inoltre, sono state eseguite misurazioni sperimentali, sia su un set-up semplificato (tubo di impedenza) sia su un mockup di una linea di scarico di un Genset marino, al fine di valutare i risultati numerici. Le simulazioni CFD e FEM validate sono poi utilizzate per l'approccio combinato che, in primo luogo, calcola il campo di flusso (velocità e temperatura) con una simulazione CFD in regime stazionario e, poi, importa questo campo nel modello acustico FEM tramite il mesh mapping per valutare la trnsmission loss della geometria studiata in presenza di flusso. L'approccio combinato è stato quindi utilizzato per valutare e modellare le proprietà acustiche sia del catalizzatore di ossidazione diesel che dello scrubber costruiti per il Genset. La loro transmission loss raggiunge valori fino a 60 dB, permettendo di eliminare il silenziatore tradizionale, riducendo così l'ingombro della linea di scarico.The development of compact abatement systems capable of reducing both NOx and SOx is of strong interest, due to the difficulty of combining both selective catalytic reduction systems and scrubber technologies on a ship. So, the research developed in this thesis comes from the need for system integration along the exhaust line to save space and the need to have a proper numerical model to simulate the acoustic properties of exhaust gas cleaning systems for their optimization. The objective of this thesis is to develop a computationally-efficient numerical methodology employing a combination of both CFD and FEM simulations, to allow the investigation and optimization of acoustic properties of exhaust line components, while respecting the limits imposed on both geometrical parameters and flow characteristics by the chemical reactions needed to satisfy NOx and SOx regulations. Some preliminary studies are performed to optimize computational effort of numerical simulations. Moreover, experimental measurements are performed on both a simplified set-up (impedance tube) and a mockup of a marine Genset exhaust line in order to assess the numerical results. The assessed CFD and FEM simulations are used for the combined approach that, firstly, calculates the flow field (velocity and temperature) with a steady-state CFD simulation and, then, imports this field into the acoustic FEM model through mesh mapping to evaluate the transmission loss of the studied geometry in presence of flow. The combined approach is then used on real systems, to assess and model the acoustics properties of both diesel oxidation catalyst and scrubber constructed for a Genset mockup. Their transmission loss reach values up to 60 dB, which allows elimination of the traditional silencer, thus reducing the overall dimensions

Safe use of pesticide in rice-fish culture

Results of the study on the relative safety of nine different pesticides: Diazinon 40% EC, Diazinon 10 G, Elsan 50% EC, Sumithion 50% EC, Furadan 3 G, Padan 50% SP, Kitazin 48% EC, Kitasin 17% G and EPN 45% EC for various fish species: Cyprinus carpio, Labeo rohita, Oreochromis mossambicus, Channa punctata, Clarias batrachus and Anabas testudineus used in rice-fish culture are presented and discussed

A Systematic Review on the Effectiveness of Different Functional Treatments for Acute Ankle Sprains

Background: An ankle sprain is a very common sport-related injury and can reduce participation in sports and employment. It can also create further complications in the function of the joint. Purpose: To evaluate the effectiveness of different functional treatments and to ascertain which functional treatment is the most effective method for acute ankle sprains. Study Design: Systematic review. Methods: The design of this systematic review was developed in accordance with PRISMA-P 2015 statement and performed according to its guidelines. A computerized literature search was performed from PubMed Central, MEDLINE via OVID and Cochrane library. Randomized controlled trials or quasi-experimental studies, published within a ten-year period (2007 to 2017), in peer-reviewed journals, with full-text articles and written in English were included in this study. Any type of functional treatments being applied to treat acute ankle sprains were considered as an intervention and only adult participants were included in this review. Surgical methods, unpublished trials, not written in the English language or not experimental research were excluded. Results: From the pooled data of this review, the stocking was more effective at improving pain, swelling, functional outcomes, range of motion, and return to sport/work, and had higher patient satisfaction than the bandage. There was no evidence that the taping and lace-up brace were more effective than other functional interventions in the treatment of acute ankle sprains. Furthermore, the prevalence of complications was greatest for the taping and lace-up brace interventions. The semi-rigid or posterior rigid support group had a better functional recovery and higher patient satisfaction, but some complications were present. Conclusion: The semi-rigid or posterior rigid support group and stocking were the most effective functional interventions for acute ankle sprain treatment. What is known about this subject: The functional treatments are becoming popular due to being effective, inexpensive and simplistic to apply. Different types of functional interventions have been used according to the choice of clinicians and patients in the treatment of ankle sprains. According to the previous researches, semi-rigid support, ankle braces, bandage and lace-up supports have greater advantages than other functional treatments from different perspectives (Example. the elastic bandage had a slower recovery rate than semi-rigid brace but less complications than taping, the lace-up support was better in swelling management than other functional treatments). What this study adds to existing knowledge: This study found that the stocking is an effective treatment for managing acute ankle sprains. It is valuable for the patient because the cost of the stocking is considerably cheaper than other functional treatments and it is very easy to wear. Some popular functional treatments like lace-up support; taping and semi-rigid braces were shown to have some complications

Thermal and Acoustic Numerical Simulation of Foams for Constructions

Cellular foams are widely employed as insulation materials, both thermal and acoustic, often in competition with traditional fibrous insulation material, e.g., rock wool. As for the acoustic and thermal properties, several models have been developed to predict acoustic properties of poroelastic materials, but they are usually applied to fibrous layers or polyurethane foams, whereas their application to new materials like complex cellular foams has not been assessed due to the different cell microstructures. There is a very strong interest both in industrial and academic in developing novel insulation materials; accordingly, the possibility of ideally designing the cellular foam microstructure to achieve desired acoustic performances appears a highly attractive target. The paper will first discuss the state-of-the-art acoustic and thermal models and their application to cellular foam materials. Then a novel sustainable alginate-based foam material will be analyzed as a case study, by focusing the aspects related to their microstructure and acoustic properties. For the derivation of an acoustic model, the determination of the parameters of Johnson-Champoux-Allard (JCA) acoustic model (tortuosity, viscous characteristic length, thermal characteristic length, porosity, and flow resistivity) was performed using five different forecasting methods, including traditional analytical model for fibrous materials as well as inverse procedure

Safe use of pesticide in rice-fish culture

Pesticides, Rice field aquaculture, Integrated farming

Experimental modal analysis of vehicle exhaust system to determine hanger location using root mean square value

Vibration of exhaust system due to the engine operation and the condition of the road surface which is transferable to the body through the hanger affects the noise, vibration and harshness performance of the vehicle, and the life time of the hangers. In order to solve this problem of the automobile exhaust system, experimental modal analysis was carried out by utilizing a sample exhaust system of passenger car as a research object within the frequency of interest. LMS Test. Lab was used to perform modal analysis. This study estimated the dynamic characteristics of the exhaust system such as natural frequencies and mode shapes. Using frequency response function at every measuring point, root mean square value (RMS) of vibrating energy was calculated to select hanger location of exhaust system where the RMS value is comparatively small. Experimental modal analysis is an efficient tool to study and estimate the dynamic properties of the exhaust system, and calculating RMS value is also an easy method to find hanger location of the exhaust system utilizing frequency response function

Sound absorption performance of sustainable foam materials: Application of analytical and numerical tools for the optimization of forecasting models

Traditional models used to predict acoustic properties of poroelastic materials are usually applied to fibrous layers or polyurethane foams. However, for new materials like complex cellular foams these procedures may not be applied due to the different cell microstructure. To this aim, the sound absorbing properties of novel sustainable foam materials are investigated as a function of the nature and loading of waste powders and their effects on the microstructure and the acoustic properties. The foams are prepared from naturally occurring alginates that are in situ polymerized. The morphology and the acoustic properties of the foam-cells appear linked to the particle size distribution of the starting powder. Determination of the parameters of Johnson\u2013Champoux\u2013Allard acoustic model (tortuosity, viscous characteristic length, thermal characteristic length, porosity and flow resistivity) was performed using five different forecasting methods, including traditional analytical model for fibrous materials as well as inverse procedure. A new procedure for tortuosity computation of foam is proposed and validated. Transfer Matrix Method calculation of the absorption coefficient was performed and compared with the experimental data, in order to assess the validity of the model. Indirect method technique is demonstrated to be dependent on experimental measurement of thermal characteristic length