94 research outputs found
Ultrahigh ionic exclusion through carbon nanomembranes
The collective “single‐file” motion of water molecules through natural and artificial nanoconduits inspires the development of high‐performance membranes for water separation. However, a material that contains a large number of pores combining rapid water flow with superior ion rejection is still highly desirable. Here, a 1.2 nm thick carbon nanomembrane (CNM) made from cross‐linking of terphenylthiol (TPT) self‐assembled monolayers is reported to possess these properties. Utilizing their extremely high pore density of 1 sub‐nm channel nm−2, TPT CNMs let water molecules rapidly pass, while the translocation of ions, including protons, is efficiently hindered. Their membrane resistance reaches ≈104 Ω cm2 in 1 m Cl− solutions, comparable to lipid bilayers of a cell membrane. Consequently, a single CNM channel yields an ≈108 higher resistance than pores in lipid membrane channels and carbon nanotubes. The ultrahigh ionic exclusion by CNMs is likely dominated by a steric hindrance mechanism, coupled with electrostatic repulsion and entrance effects. The operation of TPT CNM membrane composites in forward osmosis is also demonstrated. These observations highlight the potential of utilizing CNMs for water purification and opens up a simple avenue to creating 2D membranes through molecular self‐assembly for highly selective and fast separations
Mapping regional risks from climate change for rainfed rice cultivation in India
Global warming is predicted to increase in the future, with detrimental consequences for rainfed crops that are dependent on natural rainfall (i.e. non-irrigated). Given that many crops grown under rainfed conditions support the livelihoods of low-income farmers, it is important to highlight the vulnerability of rainfed areas to climate change in order to anticipate potential risks to food security. In this paper, we focus on India, where ~ 50% of rice is grown under rainfed conditions, and we employ statistical models (climate envelope models (CEMs) and boosted regression trees (BRTs)) to map changes in climate suitability for rainfed rice cultivation at a regional level (~ 18 × 18 km cell resolution) under projected future (2050) climate change (IPCC RCPs 2.6 and 8.5, using three GCMs: BCC-CSM1.1, MIROC-ESM-CHEM, and HadGEM2-ES). We quantify the occurrence of rice (whether or not rainfed rice is commonly grown, using CEMs) and rice extent (area under cultivation, using BRTs) during the summer monsoon in relation to four climate variables that affect rice growth and yield namely ratio of precipitation to evapotranspiration (PER), maximum and minimum temperatures (Tmax and Tmin), and total rainfall during harvesting. Our models described the occurrence and extent of rice very well (CEMs for occurrence, ensemble AUC = 0.92; BRTs for extent, Pearson's r = 0.87). PER was the most important predictor of rainfed rice occurrence, and it was positively related to rainfed rice area, but all four climate variables were important for determining the extent of rice cultivation. Our models project that 15%–40% of current rainfed rice growing areas will be at risk (i.e. decline in climate suitability or become completely unsuitable). However, our models project considerable variation across India in the impact of future climate change: eastern and northern India are the locations most at risk, but parts of central and western India may benefit from increased precipitation. Hence our CEM and BRT models agree on the locations most at risk, but there is less consensus about the degree of risk at these locations. Our results help to identify locations where livelihoods of low-income farmers and regional food security may be threatened in the next few decades by climate changes. The use of more drought-resilient rice varieties and better irrigation infrastructure in these regions may help to reduce these impacts and reduce the vulnerability of farmers dependent on rainfed cropping
Chemical ionization of phenyl n-propyl ether and methyl substituted analogs: Propene loss initiated by competing proton transfer to the oxygen atom and the aromatic ring
A chemical ionization study of deuteron transfer initiated propene loss from propoxypyridines
Modélisation des flux d’ozone en forêts pour l’évaluation des risques : état et perspectives
Detailed concept of a computer based accountancy system
A Nuclear Material Accountancy and Control System (NACS) is described, which has been developed at KFA Jülich in accordance with the requirements of the Non-Proliferation Treaty. The main features are: - recording of nuclear material in inventory items. These are to form batches wherever suitable. - extrapolation of the accounting data as a replacement for detailed measurement of the inventory items data for determination of bock inventory. Recording and control of nuclear material is carried out on two levels having access to a common data bank. The lower level deals with nuclear materials handling plus internal management while on the upper level there is a central control department which is responsible for safeguarding the nuclear materials within the entire research centre. By keeping the organizational and technical infrastructure it was possible to develop a System which is both economical and operatoreoriented. In this system the emphasis of nuclear safeguarding is placed on the acquisition of the nuclear material inventory. As rauch consideration has been given to the interests of the various operational levels and organizational units as to internal and national regulations. Since it is Part of the safeguards and control system, access to the NACS raust be restricted to a limited number of users only. Furthermore, it has a control possibility in the form of records. Authorization for access corresponds with the various tasks of the different user groups. All necessary data is acquired decentrally in the organizational units and entered via terminal. lt is available to the user groups both levels through a central data bank. By application of NACS it is possible to minimize the effort for physical inventory taking and to improve the efficiency of inspection. In order to meet all requirements, the NACS has been designed as an integrated, ocmputer-assisted information system for the automated processing of the extensive and multi-level nuclear materials data. Embedded in the preventive measures of a Nuclear Material Safeguards System, the MACS enables the operator of a nuclear plant to furnishproof of non-diversion of nuclear material
Detailkonzeption eines computergestützten Buchhaltungssystems
A Nuclear Material Accountancy and Control System (NACS) is described, which has been developed at KFA Jülich in accordance with the requirements of the Non-Proliferation Treaty. The main features are: - recording of nuclear material in inventory items. These are combined to from batches wherever suitable. - extrapolation of the accounting data as a replacement for detailed measurement of the inventory items data. Recording and control of nuclear material is carried out on two levelshaving access to a common data bank. The lower level deals with nuclear materials handling plus internal management while an the upper level there is a central control department which is responsible for safeguarding the nuclear materials within the entire research centre. By keeping the organizational and technical infrastructure it was possible to develop a System which is both economical and operator-oriented. In this system the emphasis of nuclear safeguarding is placed on the acquisition of the nuclear material inventory. As much consideration has been given to the interests of the various operational levels and organizational units as to internal and national regulations. Since it is Part of the safeguards and control system access to the NACS raust be restricted to a limited number of users only. Furthermore, it has a control possibility in the form of records. Authorization for access corresponds with the various tasks of the different user groups. All necessary data is acquired decentrally in the organizational units and entered via terminal. lt is available to the user groups on both levels through a central data bank. By application of NACS it is possible to minimize the effort for physical inventory taking and to improve the efficiency of inspection. In Order to meet all requirements, the NACS has been designed as an integrated, computer-assisted information system for the automated processing of the extensive and multi-level nuclear materials data. Embedded in the preventive measures of a Nuelear Material Safeguards System, the NACS enables the Operator of a nuclear plant to furnish proof of non-diversion of nuclear material
The Liverpool Elbow Score, patient-answered section: Cultural adaptation, validity and reliability of Turkish version.
BACKGROUND: The use of self-assessment questionnaires in addition to clinical evaluations is gradually increasing. Liverpool Elbow Scale (LES) is an elbow-specific outcome score that provides a comprehensive assessment of by both the clinicians and patients. However, it has not been adapted and validated to Turkish language. OBJECTIVE: To conduct the translation, cross-cultural adaptation and validation of Liverpool Elbow Score-patient answered outcome (LES-PAQ) into Turkish for patients with elbow fracture. DESIGN: Study of diagnostic accuracy/assessment scale. METHODS: This study was carried out in three consecutive phases: translation, cross-cultural adaptation and validation. In the third phase, we used the Quick Disabilities of the Arm, Shoulder and Hand (Quick-DASH), Mayo Elbow Performance Score (MEPS) and 12-Item Short Form Survey (SF-12) physical health score. RESULTS: Sixty-one patients were included for the analysis. Neither a ceiling nor a floor effect was observed. Cronbach's α coefficient was 0.89. Intraclass correlation coefficient was 0.94 (95% CI 0.89 to 0.96; p < 0.001). SEM was 0.28 and MDC(95) was 0.79. The LES-PAQ showed a high negative correlation with the Quick-DASH (r = -0.72, p < 0.001) and high positive correlation with MEPS (r = 0.77, p < 0.001), and with SF-12 physical health subscale (r = 0.73, p < 0.001). CONCLUSIONS: The Turkish version of the LES-PAQ is a reliable and valid tool for the assessment of the patients with elbow fracture
Is there a relation between rotator cuff injury and core stability?
BACKGROUND: Strong core stabilization not only minimizes the load on the vertebral column, but also improves strength and endurance of peripheral joints, and enables the energy transfer to distal segments. Despite the current interest surrounding core stability, none of the studies investigated the effect of core stability on the formation of rotator cuff tear or healing after repair. OBJECTIVE: To determine the relationship between core stability and upper extremity functional performance in patients who underwent rotator cuff repair surgery and to compare those with healthy subjects of similar age. METHODS: Patients who underwent rotator cuff repair (RC repair group, n= 58 patient) and healthy subjects of the similar age group (control group, n= 114) were included in the study. The mean age was 55.03 ± 9.84 years in the RC repair group and 52.71 ± 6.31 years in the control group. The RC repair group took standardized rehabilitation. The rehabilitation program did not include core strength and stability exercise. Core endurance was assessed with Flexor Endurance, Prone Bridge and Supine bridge test. Disabilities of the Arm, Shoulder and Hand (DASH), Short Form-36 (SF-36) and the Close Kinetic Chain Upper Extremity Stability (CKCUES) test were used to evaluate the upper extremity functional performance. RESULTS: The core endurance (prone and supine bridge test) of the control group was statistically significantly better than the RC repair group (p⩽ 0.005). The DASH-T, SF-36 and CKCUES scores of the control group were also statistically significantly better. CONCLUSION: The neuromuscular system should be considered as a whole, and addition of the core stabilization exercises to an effective rehabilitation program after RC repair surgery may be beneficial
Validity and Reliability of Turkish Version of Olerud-Molander Ankle Score in Patients With Malleolar Fracture.
The present study was planned to translate and culturally adapt the Olerud-Molander Ankle Score (OMAS) and assess the validity and reliability of the Turkish translation of the OMAS in patients with surgically treated malleolar fracture. The OMAS was adapted for use in Turkish by first translating it and then back-translating it in accordance with published guidelines. The final Turkish version of the OMAS was administered to 91 patients participating in the present study. The OMAS questionnaire was repeated 7 days later to assess test-retest reliability. Spearman's rank correlation analysis was used for each question's score and the total score, and the intraclass correlation coefficient was calculated for test-retest reliability. The internal consistency of the OMAS-TR was assessed using Cronbach's α. Concurrent validity was evaluated by comparing the OMAS with the Foot and Ankle Outcome Score and global self-rating function (GSRF). The GSRF has 5 options: very good, good, fair, poor, and very poor. These are assessed using a 5-point Likert scale. Before validity analysis, the GSRF score was reduced to 3 groups. In the test-retest reliability assessment, the OMAS showed high correlation (r = 0.882). The intraclass correlation coefficient was 0.942. Cronbach's α was 0.762 and 0.731 at days 1 and 7 (adequate internal consistency). The correlation coefficients versus the 5 subscales of the Foot and Ankle Outcome Score ranged from r = 0.753 to r = 0.809 (p = .000) and versus the GSRF was r = -0.794 (p = .000). According to results of the present study, the Turkish version of the OMAS demonstrated adequate test-retest reliability, excellent internal consistency, and evidence of validity for Turkish-speaking patients treated surgically for ankle fracture
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