Building Resilience Through Disaster Waste Management——UN Environment's Experiences and Approaches

Integrating disaster waste issue is a critical component of making humanitarian action fit for the future,anticipating global risks and challenges such as increased vulnerability due to climate change and environmental degradation.This requires a fundamental shift towards a model that not only strengthens the response to crises but also learns and adapts in order to anticipate and act before such waste garnered.This article conducted analyses on the characteristics of disasters in the past two decades.Uncertainties confound disaster waste management,including the timing and magnitude of each disaster,and the amounts and types of waste that will be generated.For these reasons alone,disaster waste management must be an integral part of development planning and processes.Making 10 years since the 2008 Wenchuan earthquake,this article highlights that disaster waste management is not only debris clearance or waste management following a disaster,but also includes prevention and pre-disaster preparedness aspects in terms of enhancing resilience of local communities.Such"mainstreaming,"ensures that disaster waste management(DWM)will be treated as a priority issue,on an ongoing basis.Based on UN Environment's experiences and approaches,this paper emphasises that preparedness is the key,and that priority should be accorded to integrating disaster contingency planning in national and city level waste management strategies as well as mainstreaming waste management issues within broader disaster preparedness and response plans and actions.It is envisaged that the issues presented and the gaps identified in this paper will provide a basis for future comprehensive and cohesive research on disaster waste management.In turn,this research can lead to better preparedness and response on disaster waste management.     

Effect of zinc on the electrocrystallization of cobalt

The effects of zinc on the current efficiency, power consumption, deposit quality and contamination of cathode deposit during electrocrystallization of cobalt were studied. The presence of zinc affected current efficiency at all temperatures and the effect was intensified at lower temperature. Increase in power consumption was significant at lower temperature. The quantity of zinc in the electrodeposited cobalt invariably increased with increase in zinc concentration in the electrolyte, however, the zinc content of the deposit was significantly low at higher temperature. The tolerance limit of zinc in the electrolyte with respect to deposit quality was also greater at higher temperature. Increase in current density decreased the current efficiency, increased the power consumption and lowered the cathode contamination.     

氨浸出混合铜矿石的表征及动力学(英文)

研究了含8.8%Cu和36.1%Fe的混合铜矿石的氨浸出动力学。矿物学表征表明,该矿石的含铁成分以菱铁矿为主,硫化矿以黄铜矿为主。研究了工艺参数,如搅拌速度、反应温度、氨浓度、矿石粒径、氧分压对氨浸出过程的影响。在标准的浸出条件下,即粒径125~212μm、反应温度120°C、NH3浓度1.29 mol/L、氧分压202 kPa,在2.5 h内Cu的浸出率达到83%。在使用较高浓度的氨和较小粒径的矿石时,Cu的浸出率能够达到95%。动力学研究结果表明,浸出过程为表面反应控制,估算出的活化能为(37.6±1.9)kJ/mol,氧分压与氨浓度的反应级数分别为0.2和1。     

Buckling analysis and small scale effect of biaxially compressed graphene sheets using non-local elasticity theory

In this paper, buckling analysis of biaxially compressed graphene sheets with non-local elasticity theory is reported. The equations of motion for graphene sheet are derived using non-local local elasticity theory. Levy??s approach has been used to solve the governing equations for various boundary conditions of the graphene sheet. Present results from Levy??s solution agree with the results for all edges simply supported available in the literature. Further, the effect of the (i) non-local parameter, (ii) size of the graphene sheet and (iii) various boundary conditions on the critical buckling loads of the graphene sheets are investigated. It is observed that non-local parameter and boundary conditions significantly influence the critical buckling loads of the small size graphene sheets.     

Voltage control in 3-phase stepped-wave inverters

Abstract

A number of voltage-control schemes in 3-phase bridge inverters are investigated. These control schemes are applied to dual 3-phase cascaded bridge inverters with fifth- and seventh-harmonic neutralization to realize pulse-width and amplitude controlled waveforms. kVA ratings of filter components are calculated to realize a total harmonic distortion of 5% in the output waveform. The control scheme with two pulses per half cycle spaced 60° apart in individual inverters gives the lowest total harmonic distortion and requires the lowest filter kVA rating. The theoretical results are experimentally verified and are in closo agreement.     

SST-1 Refurbishment Progress: an Update

Refurbishment of steady state tokamak (SST-1) primarily focused at addressing the issues and bottle-necks involving various subsystems of SST-1 as observed during earlier commis- sioning attempts, have progressed significantly. Under the refurbishment spectrum, all joints in the superconducting magnet system have been re-fabricated as low DC leak tight joint resistances, all toroidal field (TF) magnets have been equipped with 5 K radiation shields on the inner side and successfully tested for their rated parameters in cold under nominal currents, all vessel sectors and modules have been baked and tested under representative conditions, supporting helium and ni- trogen cryogenic facilities have been made > 99% reliable in various envisaged operating scenarios of SST-1. The reassemblies of the critical subsystems of the SST-1 machine shell have progressed aggressively and are nearing completion. Auxiliaries such as the baking facility for the vacuum vessel and first wall components, current leads assembly distributions, synchronized timing sys- tem, reliable data acquisition and plasma control systems as well as essential diagnostics have also been readied towards the first plasma. A detailed engineering validation of the assembled SST-1 machine shell including field error measurements has been planned prior to first plasma attempts.     

Thermo mechanical buckling analysis of carbon nanotubes on winkler foundation using non-local elasticity theory and DTM

Thermo-mechanical buckling behaviour of Single Walled Carbon Nanotube (SWCNT) on Winkler foundation is reported. Non-local elasticity theory and differential transformation method are applied. Effects of (i) size of SWCNT, (ii) non-local parameter, (iii) Winkler modulus, (iv) boundary conditions and (v) temperature on buckling load are investigated.     

Characterization and kinetic study on ammonia leaching of complex copper ore

Ammonia leaching kinetics of a complex Cu-ore assaying 8.8% Cu and 36.1% Fe was examined. Mineralogical characterization indicated that the major phase of the ore was siderite with chalcopyrite as the major sulfide mineral. The effects of parameters such as agitation, temperature, NH₃ concentration, particle size and oxygen partial pressure (p_O2) were investigated. Under the standard leaching conditions of 125–212 µm particle size, 120 °C, 1.29 mol/L NH₃ and 202 kPa of p_O2, about 83% Cu could be selectively extracted in 2.5 h. However, when using higher NH₃ concentration and lower particle size, more than 95% extraction was achieved. The leaching process was found to be surface reaction controlling. The estimated activation energy was (37.6±1.9) kJ/mol and empirical orders of reaction with respect to p_O2 and [NH₃] were about 0.2 and 1, respectively.     

Heat conduction and thermal stabilization in YBCO tape

Yttrium barium copper oxide (YBCO) coated conductors are widely used in the conduction-cooled superconducting magnets with rapid development in refrigeration technologies at present. ‘Quench’ is a state that refers to the irreversible and uncontrolled superconductor to resistive transitions in the superconductor. The propagation of ‘quench’ or ‘normal zone’ has different characteristics in these high temperature superconductors (HTS) compared to low temperature superconductors. The superconductor to normal index, known as ‘n’ is much flatter in HTS. The hot spot emerging in local region due to quench and non-uniform critical current may cause permanent damage to whole HTS tape and hence the magnet winding pack. Thus it is necessary to determine the temperature profile along the length of HTS tape under a given energy (joule heating) such that propagation of the hot spot developed locally can be prevented early. In this study, a one dimensional, time dependent heat diffusion equation with appropriate boundary conditions are used to describe the consequences of the normal zone propagation resulting in the temperature diffusion in a HTS tape. The results demonstrate the necessity of adequate cooling of the edges of the flat HTS tapes to prevent irreversible normal zone transitions.     

废镍催化剂回收制备纤维状氢氧化镍

研究从废旧镍催化剂中回收镍以制备氢氧化镍。采用酸浸法,在90℃下用1mol／L硫酸浸没废镍催化剂,从中提取镍。向净化后的含镍溶液中加入NaOH,分别采用3种不同的方法,即尿素水解、传统方法和水热方法制得3种不同的氢氧化镍,分别命名为Ni（OH）2-U,Ni（OH）2-C和Ni（OH）2-H。与传统方法相比,采用水热方法制得的氢氧化镍具有更好的结晶度。Ni（OH）2-C和Ni（OH）2·H都含有β-Ni（OH）2与a-Ni（OH）2·0．75H20的混合相,而Ni（OH）2．U只含有a-Ni（OH）2．0．75H20相。TEM观察显示Ni（OH）2-U样品具有棒状结构。在这3种样品中,Ni（OH）2-U表现出最好的电化学活性。