Acceptable Recovery Time Research Articles

Room temperature detection of aspergillus flavus volatile organic compounds (VOCs) under simulated conditions using graphene oxide and tin oxide Nanorods (SnO2 NRs-GO)

This study investigated the application of a hybrid nanocomposite of tin oxide nanorods (SnO2 NRs) and graphene oxide (GO) for the chemoresistive detection of some volatile compounds (hexanal, benzaldehyde, octanal, 1-octanol, and ethyl acetate vapours) emitted by Aspergillus flavus under simulated conditions. The synthesised materials were characterised using various analytical techniques, including high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, and Fourier transform infrared spectroscopy (FTIR). Three sensors were fabricated: individual nanomaterials (i.e., SnO2 and GO) and composites (SnO2-GO). The results showed that SnO2 NRs had limited sensitivity as a sensor, while GO-based sensors responded to various analyte vapours. However, the incorporation of SnO2 NRs into GO layers resulted in synergistic effects and improved sensor performance. The sensors' sensitivity, selectivity, recovery, and response times were quantitatively determined from the sensors' response curves. The nanocomposite sensor demonstrated superior sensitivity and selectivity for analyte vapours with acceptable response and recovery times. In addition, the sensor was insensitive to humidity and showed robust performance up to 62% RH, although sensor drift occurred at 70% RH. This study highlights the promising potential of using SnO2 NRs-GO composite-based sensor for sensitive and selective detection of analyte vapours, which has significant implications for food safety and environmental monitoring applications.

A comparison study on the acetone sensing performance of preeminent nanostructures of SnO2 for diabetes diagnosis

Metal oxide semiconductor-based acetone sensors are of great need owing to their cost-effective easy production for real-time applications. Experiments on different morphologies of metal oxide nanostructures are gaining momentum for enhancing acetone sensing properties. 1D nanofibers and dangling bonds-rich facet exposed materials are eminent nanostructures in this field. In this article, we compare the acetone-sensing abilities of these nanostructures, including nanofibers and facet-exposed nanostructures. Acetone sensing qualities of the fabricated sensors were tested at different temperatures varying from 100 to 350 °C. Due to a significant number of dangling bonds on the surface, the octahedral nanoparticle sensor produced a higher response than the other sensors. At their respective operating temperatures, each of the manufactured sensors was capable of detecting a very low concentration of acetone (1 ppm). All of the samples had acceptable response and recovery times. The octahedral nanoparticle sensor’s excellent repeatability, reproducibility, and long-term stability made it a good choice for real-time detection of acetone in the exhaled breath of individuals with diabetes. In patients with diabetes, the exhaled breath exhibits an acetone concentration exceeding 1.8 ppm, whereas in healthy persons, this concentration typically falls between the ranges of 0.3–0.9 ppm.

Comparative spectroscopic study of Tb:Ce(Sal)3Phen complex inhibited PVA nanofibres for flexible moisture sensor

In the present work, we report a systematic study on optical alteration in Tb:Ce(Sal)3Phen, Tb(Sal)3Phen complexes, and TbCl3·6H2O inhibited in polyvinyl alcohol (PVA) polymeric nanofibres. We also report the feasibility of Tb:Ce(Sal)3Phen complex dispersed electrospun nanofibres for opto-humidity sensor. Structural, morphological, and spectroscopic properties of the synthesized nanofibres were systematically compared using Fourier transform infrared spectroscopy, scanning electron microscopy, and Photoluminescence analysis. Synthesized Tb(Sal)3Phen complex inhibited in nanofibres yields characteristic bright green photoluminescence of Tb3+ under UV excitations, which is at least two manifolds enhanced on the addition of Ce3+ ions in the same complex. The presence of Ce3+ ions, the salicylate ligand, and the Tb3+ ion help to expand the absorption range (290 nm–400 nm) and, subsequently, the photoluminescence in blue and green regions. Our analysis revealed the linear enhancement of photoluminescence intensity with the addition of Ce3+ ions. Upon exposing the flexible Tb:Ce(Sal)3Phen complex dispersed nanofibres mat in different humidity environments, photoluminescence intensity shows a linear variation. The prepared nanofibres film shows good reversibility, small hysteresis, cyclic stability, and acceptable response and recovery times i.e. 35 and 45 s. The humidity sensing mechanism was proposed on the basis of infrared absorption analysis of dry and humid nanofibres.

A comparative DFT study on Al- and Si- doped single-wall carbon nanotubes (SWCNTs) for Ribavirin drug sensing and detection

In this work, we have presented a comparative study on Ribavirin (RBV) drug sensing and detection on the pristine and functionalized single-wall carbon nanotubes (f-SWCNTs) by Density Functional Theory (DFT) method. The pristine and metal-doped zigzag (4,0) and (6,0) SWCNTs were first considered for the RBV adsorption. All the probable positions of RBV adsorption were investigated to find which one is energetically favourable. The topology analysis of the Quantum theory of atoms in a molecule (QTAIM) with non-covalent interactions (NCI-RDG), Frontier molecular orbitals (FMO), Density of states (DOS), and non-linear optical (NLO) analysis were carried out to understand the molecular structure, electrical, electronic and optical properties of complexes. The charge analysis indicates that charge transfer is from the adsorbed RBV to the pristine and metal-doped (4,0) and (6,0) SWCNTs. The highest values of adsorption energies for Al-, Si-doped and pristine (4,0) SWCNTs were determined as −34.688, −87.999 and −10.382 kcal/mol, respectively, whereas corresponding values for metal-doped and pristine (6,0) SWCNTs are about −43.592, −20.661 and −12.414 kcal/mol, respectively. The results suggest that those bare and metal-doped (4,0) SWCNTs and (6,0) Si-SWCNTs can serve as promising sensors in practical applications to detect, recognize and carrier RBV drug for its medicinal drug delivery applications. Based on the NLO properties of (6,0) Si-SWCNTs and pristine (6,0) SWCNT (with an acceptable recovery time of 279s and first hyper polarizability value of β = 229.25 × 10−30 cm5 esu−1), those nanotubes may be possible candidates to be used as the optoelectronic sensor for RBV drug. The appropriate short length of nanotubes was obtained.

MOF-derived In2O3 microtubes as an effective sensing material for sub-ppm-level triethylamine detection

The development of triethylamine (TEA) gas sensors play an important role in industrial gas detection and environmental quality analysis. In this work, the TEA gas sensor was prepared porous In2O3 microtubes synthesized by hydrothermal treatment and annealing process. The morphological characterization displayed that the length of the porous In2O3 microtube was approximately 7∼9 μm and the diameter was around 0.8∼1.1 μm. Gas sensing measurements indicated that the sensor based on the porous In2O3 microtubes exhibited a superior response to 1 ppm TEA (Ra/Rg = 145) at 140 °C, short response time (5) and acceptable recovery time (20 s), good reversibility, excellent selectivity and the TEA detection limits as low as 100 ppb. The possible response mechanism is also discussed carefully through density functional theory (DFT) calculation, which illuminates that the porous In2O3 microtubes are expected to be potential candidates for TEA detection in practical application.

Nickel Oxide-Carbon Soot-Cellulose Acetate Nanocomposite for the Detection of Mesitylene Vapour: Investigating the Sensing Mechanism Using an LCR Meter Coupled to an FTIR Spectrometer.

Nanocomposite sensors were prepared using carbon soot (CNPs), nickel oxide nanoparticles (NiO-NPs), and cellulose acetate (CA), which was used to detect and study the sensing mechanism of mesitylene vapour at room temperature. Synthesised materials were characterised using high-resolution transmission electron microscopy (HR-TEM), powder x-ray diffraction (PXRD), Raman spectroscopy, and nitrogen sorption at 77 K. Various sensors were prepared using individual nanomaterials (NiO-NPs, CNPs, and CA), binary combinations of the nanomaterials (CNPs-NiO, CNPs-CA, and NiO-CA), and ternary composites (NiO-CNPs-CA). Among all of the prepared and tested sensors, the ternary nanocomposites (NiO-CNPs-CA) were found to be the most sensitive for the detection of mesitylene, with acceptable response recovery times. Fourier-transform infrared (FTIR) spectroscopy coupled with an LCR meter revealed that the mesitylene decomposes into carbon dioxide.

An analytical framework to assess earthquake-induced downtime and model recovery of buildings

While modern seismic design codes intend to ensure life-safety in extreme earthquakes, policy-makers are moving toward performance objectives stated in terms of acceptable recovery times. This article describes a framework to probabilistically model the post-earthquake recovery of buildings and provide quantitative seismic performance measures, expressed in terms of downtime, that are useful for decision-making. Downtime estimates include the time for mobilizing resources after an earthquake and conduct necessary repairs. The proposed framework advances the well-established Federal Emergency Management Agency (FEMA) P-58 and Resilience-based Earthquake Design initiative (REDi) methodologies by modeling temporal building recovery trajectories to target recovery states, such as stability, shelter-in-place, reoccupancy, and functional recovery. The shelter-in-place recovery state accounts for relaxed post-earthquake habitability standards, in contrast with the reoccupancy recovery state that relates to pre-event habitability criteria. Analogous to safety-based codes, which specify a threshold for the probability of collapse under a given ground motion shaking intensity, this framework permits evaluating the probability of a building not achieving a target recovery state, for example, shelter-in-place, immediately after an earthquake, or, alternatively, the probability of achieving a target recovery state, for example, functional recovery, within a specified time frame. The proposed framework is implemented to evaluate a modern 12-story residential reinforced concrete shear wall building in Seattle, WA. The assessment results indicate that under a functional-level earthquake (roughly equivalent to ground motion shaking with a return period of 475 years), the probability of not achieving shelter-in-place immediately after the earthquake is 22%, and the probability of downtime to functional recovery exceeding 4 months is 88%, which far exceeds acceptable thresholds suggested in the 2015 National Earthquake Hazards Reductions Program (NEHRP) guidelines and FEMA P-2090.

Development of seismic resilience index methodology for RC structures via functionality curve

Seismic resilience index (SRI) approach describes the post-seismic recovery phase of a single building by incorporating the time dimension. In recent decades, numerous quantitative frameworks have been developed to quantify earthquake resilience. The seismic resilience of existing reinforced concrete (RC) structures in Malaysia under far-field (FF) and near-field (NF) earthquake scenarios is examined in this research methodology using a seismic resilience index (SRI) and functionality curve. SRI is implemented to a four-story RC school building and a five-story RC hospital structure damaged by the 2015 Ranau earthquake. In addition, a total of 25 existing RC structures have been selected as target case studies for evaluating the SRI and presenting the results graphically using the Geographical Information System (GIS) platform. These buildings are primarily divided into three clusters: low, mid, and high rise. Non-linear dynamic analysis (NL-DA) is utilized in this approach to analyze the case studies and the selected buildings using the Finite Element platform (FE). Moreover, a group of seismic records encompassing of far-field and near-field are selected for simulation process using non-linear time history analysis (NL-THA). Eventually, Incremental Dynamic Analysis, fragility and vulnerability assessment, functionality assessment, time of recovery (TREC), loss of resilience (LOR), robustness (R) and SRI indicator are all part of this approach.•SRI helps decision-makers create or suggest repair or retrofitting solutions with acceptable recovery time and cost.•The consequences of failures for people's lives, properties, as well as the economy, will be mitigated.•Improve the sustainability and serviceability of structures to ensure seismic safety and meet Sustainable Development Goal 11.

Carbazochrome carbon nanotube as drug delivery nanocarrier for anti-bleeding drug: quantum chemical study.

The interaction between drugs and single-walled carbon nanotubes is proving to be of fundamental interest for drug system of delivery and nano-bio-sensing. In this study, the interaction of pristine CNT with carbazochrome, an anti-hemorrhagic or hemostatic agent, was investigated with M06-2X functional and 6-31G* basis set. All probable positions of related adsorption for these kind drugs were thought-out to find out which one is energetically suitable. Based on the achieved data, the stronger interactions appeared the oxygen atom of C = O group and nitrogen atom of imine groups. The topology analysis of QTAIM (quantum theory of atoms in a molecule) method was accomplished to understand the properties of interactions between the CNT and carbazochrome. Frontier molecular orbital energies of all systems, global index including stiffness, softness, chemical Gibbs energies, and electrophilicity parameters, as well as some other important physical data such as dipole moment, polarizability, anisotropy polarisibility, and hyperpolaribility were calculated, evaluated, and then compared together. The essence of the formed bonding model progress along the reaction roots was further validated using electron localization function (ELF) calculations. The highest values of adsorption energies were determined in the range of 18.24 up to 22.12kcalmol-1 for these kind systems. The acceptable recovery time of 849s was obtained for the desorption of carbazochrome from the CNT surface under UV-light. The final results exhibit that carbazochrome can serve as a promising carrier and also as sensitive sensors in any kind of practical application.

SecNVM: An Efficient and Write-Friendly Metadata Crash Consistency Scheme for Secure NVM

Data security is an indispensable part of non-volatile memory (NVM) systems. However, implementing data security efficiently on NVM is challenging, since we have to guarantee the consistency of user data and the related security metadata. Existing consistency schemes ignore the recoverability of the SGX style integrity tree (SIT) and the access correlation between metadata blocks, thereby generating unnecessary NVM write traffic. In this article, we propose SecNVM, an efficient and write-friendly metadata crash consistency scheme for secure NVM. SecNVM utilizes the observation that for a lazily updated SIT, the lost tree nodes after a crash can be recovered by the corresponding child nodes in NVM. It reduces the SIT persistency overhead through a restrained write-back metadata cache and exploits the SIT inter-layer dependency for recovery. Next, leveraging the strong access correlation between the counter and DMAC, SecNVM improves the efficiency of security metadata access through a novel collaborative counter-DMAC scheme. In addition, it adopts a lightweight address tracker to reduce the cost of address tracking for fast recovery. Experiments show that compared to the state-of-the-art schemes, SecNVM improves the performance and decreases write traffic a lot, and achieves an acceptable recovery time.

Fully inkjet-printed BaTiO3 capacitive humidity sensor: Microstructural engineering of the humidity sensing layer using bimodal ink

Humidity sensors are often used in industries where humidity levels must be monitored due to their possible effects on the manufacturing processes and products. These sensors must possess high sensitivity that can detect changes in the environment's humidity level. This paper presents a novel technique to improve the sensing performance of humidity sensors by varying the microstructure of the BaTiO3 humidity sensing layers by optimizing the mixing ratios of the bimodal inks deposited by the inkjet printing technique. By varying the mixing ratio of bimodal inks, the surface area, pore size, and packing density of the humidity sensing layers were modulated because of the incorporation of smaller particles into larger particles. The optimal sensor was produced by a 70:30 mixing ratio due to its higher surface area, which allowed a higher area for water adsorption and therefore improved the humidity sensitivity. Microstructural analyses, such as Focused-Ion-Beam Field-Emission Scanning Electron Microscope (FIB FE-SEM), image analysis, and Brunauer–Emmett–Teller (BET) were performed to examine the microstructural differences of the sensors. The fully inkjet-printed BaTiO3 capacitive sensors, which had the optimal mixing ratio, exhibited a high sensitivity of 5.75 × 105 pF/%RH, which exceeded that of most reported humidity sensors, good repeatability, a linearity of 0.989, an acceptable response and recovery time of 41 s and 34 s, respectively, low hysteresis, and good stability over a long period of time. The fabricated BaTiO3-based capacitive humidity sensor exhibited an outstanding performance that can be utilized toward various applications.

Study of MWCNT / SnO2/Ru thick-film sensors for detecting the presence of certain harmful gases in air

Thick-film VOCs sensors based on ruthenated multi-walled carbon nanotubes coated with tin-dioxide nanoparticles (MWCNTs/SnO2) nanocomposite structures are prepared using three methods: hydrothermal synthesis, sol–gel technique and their combined method. It is shown that the optimal conditions for applications as acetone and toluene as well as ethanol and methanol vapors sensors in view of high response and selectivity relative to each other depend on choice of material synthesis method, mass ratio of the nanocomposite components and selected operating temperature. Selective sensitivity to acetone and toluene vapors at 150oC operating temperature MWCNTs/SnO2 are shown sensor structures with the mass ratio of the components 1:4 and 1:24, respectively. The samples with 1:200 mass ratio of the nanocomposite components are shown the selective response to acetone vapor exposure in the range of 200-250oC operating temperatures. The high sensitivity to ethanol and methanol vapors at 200oC operating temperature was revealed for the sensor structures made by different methods with the 1:8, 1:24, 1:50 and 1:66 ratios of the components, respectively. The results of research works related to the study of thick-film multiwall carbon nanotube– tin oxide nanocomposite sensors of propylene glycol (PG), dimethylformamide (DMF) and formaldehyde (FA) vapors are also presented in this paper. Investigations of response–recovery characteristics in the 50–300oC operating temperature range reveal that the optimal operating temperature for PG, DMF and FA vapor sensors, taking into account both high response and acceptable response and recovery times are about 200 and 220oC, respectively. The dependence of the sensor response on gas concentration is linear in all cases. Minimal propylene glycol, dimethylformamide and formaldehyde gas concentrations, where the perceptible signal was noticed, were 13, 5 and 115 ppm, respectively.

Tin Oxide/Carbon Nanotube Nanocomposite Sensors for Some Toxic VOCs Detection

Thick-film VOCs sensors based on ruthenated multi-walled carbon nanotubes coated with tin-dioxide nanoparticles (MWCNTs/SnO2) nanocomposite structures are prepared using three methods: hydrothermal synthesis, sol–gel technique and their combined method. It is shown that the optimal conditions for applications as acetone and toluene as well as ethanol and methanol vapors sensors in view of high response and selectivity relative to each other depend on choice of material synthesis method, mass ratio of the nanocomposite components and selected operating temperature. Selective sensitivity to acetone and toluene vapors at 150oC operating temperature MWCNTs/SnO2 are shown sensor structures with the mass ratio of the components 1:4 and 1:24, respectively. The samples with 1:200 mass ratio of the nanocomposite components are shown the selective response to acetone vapor exposure in the range of 200-250oC operating temperatures. The high sensitivity to ethanol and methanol vapors at 200oC operating temperature was revealed for the sensor structures made by different methods with the 1:8, 1:24, 1:50 and 1:66 ratios of the components, respectively. The results of research works related to the study of thick-film multiwall carbon nanotube–tin oxide nanocomposite sensors of propylene glycol (PG), dimethylformamide (DMF) and formaldehyde (FA) vapors are also presented in this paper. Investigations of response–recovery characteristics in the 50–300oC operating temperature range reveal that the optimal operating temperature for PG, DMF and FA vapor sensors, taking into account both high response and acceptable response and recovery times are about 200 and 220oC, respectively. The dependence of the sensor response on gas concentration is linear in all cases. Minimal propylene glycol, dimethylformamide and formaldehyde gas concentrations, where the perceptible signal was noticed, were 13, 5 and 115 ppm, respectively.

Mid-term results of open debridement and reattachment surgery for insertional Achilles tendinopathy: A retrospective clinical study.

The aim of this study was to determine the effects of age and body mass index (BMI) on the functional outcomes, satisfaction rates, and recovery time after open debridement and reattachment surgery in non-athletic patients with insertional Achilles tendinopathy (IAT). In this retrospective study, 33 non-athletic patients (34 ankles) in whom open debridement and reattachment surgery was performed for IAT from 2006 to 2016 were included. Change in pain intensity was assessed using a Visual Analogue Scale (VAS) preoperatively and at the final follow-up. Functional assessment was done by preoperative and postoperative American Orthopaedics Foot and Ankle Score (AOFAS) and final follow-up Victorian Institute of Sport Tendon Study Group-Achilles Tendinopathy score (VISA-A). Patient satisfaction was evaluated by Roles - Maudsley score (RMS). The recovery time was defined as the time interval from the first appearance to postoperative relief of symptoms and recording. In addition, the recurrent Haglund's deformity was determined by postoperative control radiographs. The mean age at the time of the operation was 51.19 years. The mean follow-up was 61.75±8.49 months. According to BMI, 5 patients were determined as morbid obese, 19 as obese, 3 as overweight, and 6 as normal. The mean VAS score significantly decreased from 8.5 preoperatively to 1.3 postoperatively (p<0.001). The mean AOFAS score significantly improved from 55.8 preoperatively to 92 postoperatively (p<0.001). Postoperative VISA-A score was 86% (range=32%-100%). According to RMS, 22 patients reported the result as excellent, 8 as good, 2 as fair, and 1 as poor. The mean recovery time was 11.8 (range=2-60) months, but one patient did not reach a symptom free status and thus was not included in the recovery time analysis. Postoperative control radiographs revealed signs of recurrence deformity in four patients. Recovery time showed a negative correlation with the age of the patients (r=-0.65). Postoperative scores and BMI showed no significant correlations with the recovery time on the basis of Spearman's rho test (p=0.196). The results of this study have shown that open debridement and reattachment surgery may be an effective surgical method in relieving pain and improving functional status with high satisfaction rate and acceptable recovery time in the management of non-athletic patients with IAT. Level IV, Therapeutic study.

Convenient CNT-Paper Gas Sensors Prepared by a Household Inkjet Printer.

A hydrosoluble light-sensitive polymer named PSAG (poly-styrenesulfonate acrylic acid glycidyl methacrylate) was synthesized by acrylic acid (AA), sodium 4-styrenesulfonate (SS), and glycidyl methacrylate (GMA). PSAG is used to modify multiwall carbon nanotubes (MWCNTs) with a length diameter between 0.004 and 0.016. An inkjet conductive ink was formed by well-dispersed MWCNTs in aqueous and organic solvents, which could adjust the surface tension and viscosity of the ink. Gas sensors were then fabricated using this conductive ink on a household inkjet printer. The sensors demonstrated good reproducibility and acceptable recovery time (<200 s) to ammonia, methanol, and acetone. The resistance of the inkjet-printed sensor electrodes remained stable in the process of bending the sensors to different angles because of ultraviolet curing.

Multilayer Structure of Reduced Graphene Oxide and Copper Oxide as a Gas Sensor

Reduced graphene oxide and copper oxide multilayer structures were fabricated in a planar configuration by deposition on both ceramic and Si/SiO2 substrates with interdigitated Au electrodes by the spray method. SEM (scanning electron microscopy), TEM (transmission electron microscopy), XRD (X-ray diffraction), and elemental analysis investigations indicated that graphene oxide (GO) was obtained in a form of interconnected flakes consisting of 6–7 graphene layers for GO with the total thickness of ca. 6 nm and 2–3 layers for rGO with the total thickness of 1 nm. The lateral size of one flake reached up to 10 micrometers. Copper oxide was obtained by the wet chemical method. The number of sequential layers of the sensing structure was optimized to obtain good sensitivity and acceptable response/recovery times in response to the oxidizing nitrogen dioxide atmosphere. Both semiconductor partners revealed p-type conductivity. Formation of isotype heterojunctions between both semiconductor partners was taken into account and their influence on electrical transport explained. Optimized sensor structures revealed relative sensitivities reaching several tens of percent and acceptable response and recovery times in NO2 concentration ranged from a few to 20 ppm. Possibility of manufacturing sensors working at room temperature was shown, but at the cost of prolonged response/recovery times.

Electrodeposition of Polyaniline/Three- Dimensional Reduced Graphene Oxide Hybrid Films for Detection of Ammonia Gas at Room Temperature

Reliable, sensitive and selective ammonia gas sensing at room temperature is very important for monitoring the environment for hazardous pollutants. In this study, ammonia (NH3) gas sensor is proposed based on polyaniline/three-dimensional reduced graphene oxide (PANI/3D-RGO) hybrid samples, which are loaded on glass substrates by electrochemical polymerization method. The PANI/3D-RGO hybrid samples with different weight percentages of 3D-RGO (weight% =0.05, 0.2, 0.5 and 1) are characterized by field emission-scanning electron microscopy, Fourier transform infrared and X-ray diffraction. The specific surface area is analyzed by the Brunauer-Emmett-Teller (BET) equation. The gas-sensing performances of the fabricated sensors indicate that PANI/3D-RGO (0.2wt. %) exhibits the best response for 50 ppm NH3 gas at room temperature, this sensor response to lower concentrations of NH3 (5ppm, 10 ppm and 25 ppm) too. The PANI/3D-RGO (0.2wt. %) hybrid sensor shows represent response values of about 3.72 and acceptable response and recovery times (98 s and 288 s) to 50 ppm NH3 which is about 4.27 fold higher than that of pure PANI in 50 ppm NH3 gas. The excellent sensing performance of the developed gas sensor can be attributed to the synergetic effects of PANI and 3D-RGO, $\pi -\pi $ interaction between the two components, efficient increase in hole-like carriers and substantial increase in active sites.

Performance Evaluation and Disruption Recovery for Military Supply Chain Network

The performance of military supply chain networks (MSCNs) against disruptions is an important consideration for defense logistics decision making, and it is crucial to evaluate it scientifically and accurately. This paper highlights the problem from the perspective of targeted defense strategies before being attacked and analyzes the acceptable recovery time against attacks. A topological structure model, with three exclusive features, in contrast with traditional networks, is used to describe the structure of military supply chain networks. In order to provide a platform for evaluating performance, a simulation method based on exploratory analysis is presented. Considering supply capability against disruptions and the acceptable recovery time for an MSCN after disruptions, evaluation metrics including supply capability and disruption recovery are proposed. By applying the model and algorithms to a POL supply network in a theater, we obtain the values of supply capability and disruption recovery against different disruptions. We also identify the key entities which can easily cause catastrophic failure to this network and which need to be protected against carefully. The results show that new evaluation metrics can capture important performance requirements for military supply chain networks. We also find that the proposed method in this paper can solve the problem of evaluating performance and analyzing disruption recovery in a feasible and effective manner.

The Efficacy of Poppy, Papaver nudicaule extract as an Anesthetic for the Common Carp, Cyprinus carpio

Aqueous extract of poppy plant) Papaver nudicaule) with five concentrations (50, 100, 150, 200 and 250) mg/l were used to anesthetize fingerlings of the common carp Cyprinus carpio (Mean total length 8.91 ± 0.31 cm and mean total weight 7.72 ± 1.19 gm) instead of the traditional use of MS-222. Results showed that extracted solution of poppy have partial and overall anesthesia effect on these fishes with inverse relationship between the concentrations used and the time needed to reach partial and overall anesthesia, and also direct relationship between concentrations used and time needed for fish recovery. Best results were obtained by using a concentration of 250 mg/l, where time for partial anesthesia was 8 ± 1.52 min., time for overall anesthesia was 10 ± 1.70 min., time needed for partial recovery was 25 ± 2.43 min. and time needed for overall recovery was 35 ± 2.23 min. Fish behavior observations revealed a difference ranging from slow swimming with increasing in breathing rates movements to vertical swimming near the surface, then laying at bottom and too much decrease in breathing rates movements. Results appeared that there were no significant differences (p≥0.01) between glucose concentration in fish blood plasma after recovery and control fishes. So it was concluded that these. The results showed also that there were no significant differences (p≥0.01) in ALP, AST, ALT, LDH and CK among fishes after recovery comparing with the control fishes. Experimental fishes exhibited no stress during anesthesia by using poppy extracted solution. This indicated that the treated fishes exhibited no physiological effects stress which might lead to poor health condition later. The study demonstrated that poppy can be used as an effective anesthetic, as we obtained acceptable induction and recovery times. The poppy can be recommended as suitable anesthetics for fishes (200 or 250 mg/l).

FTLink: Efficient and flexible link fault tolerance scheme for data plane in Software-Defined Networking

Link fault tolerance has been a hotspot in Software-Defined Networking (SDN) for many years. Both proactive and reactive schemes are proposed to guarantee network availability and robustness. However, the former wastes plenty of Ternary Content Addressable Memory (TCAM) and bandwidth resources, while the latter faces long fault recovery time.In this paper, we propose FTLink, an efficient and flexible link fault tolerance scheme in SDN. Firstly, through collecting the current network state information, we pre-generate a set of backup links for each link of the primary path of the flow. We formulate the backup links planning as a multi-objective optimization problem that minimizes the required switch TCAMs and link bandwidths. Combining flow characteristics, we develop a two-step heuristic algorithm, namely planning backup links for each link that transmits elephant flows with the greedy tracing method in step 1 and for each link that transmits mice flows with the bidirectional searching method in step 2, to determine the backup links set. Then, we introduce a global matching table in the controller to maintain the generated backup links and additional flow rules. Once monitoring a faulty link, FTLink looks up the matching table entries and enables the backup links via installing the additional flow rules into the switches to realize flexible fault recovery. Simulations show that FTLink is effective in terms of high-efficiency TCAM and bandwidth usage and produces an acceptable recovery time of less than 30 ms, compared with baseline schemes. The prototype tests under realistic network further confirm the efficiency of FTLink.