Metallic resources in smartphones Bookhagen, B.; Bastian, D.; Buchholz, P. ...
Resources policy,
October 2020, 2020-10-00, 20201001, Letnik:
68
Journal Article
Recenzirano
53 metallic elements from smartphones were investigated with regard to metal prices, metal production, and content in comparison to mined ores. The metal content of the 7.42 billion smartphone ...devices sold from 2012 to 2017 could theoretically maintain the global supply for 91 days for Ga, 73 days for Ta, 23 days for Pd, 14 days for Au, and 6 days for REE. The pure metal value of a single smartphone device for the investigated metals currently sums to 1.13 US $; it averaged at 1.05 US $ from 2012 to 2017 with the highest value of 1.32 US $ in 2012. The Au content is low (16.83 mg per device), yet constitutes the highest value with a current share of approximately 72% of total value for all measured metals, followed by Pd (10%). Approximately 82% of total metal value can be recycled with current standard recycling methods for Au, Cu, Pd, Pt, which only comprise 6 wt% of the total device. The printed circuit board (pcb) contains 90% of the measured Au, 98% of Cu, 99% of Pd, 86% of In, and 93% of Ta. The Au, Pd, Cu, Pt, Ta, In, Ga contents in a smartphone pcb are significantly higher than the metal content in currently mined ores. Magnets contain 96% of the measured REE and 40% of the measured Ga, with higher concentrations than ores for REE and Ga. For Co and Ge, metal content in smartphones (w/o batteries) is lower than in ores.
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•Detailed content of 53 metals from smartphones is investigated.•Metal concentrations in smartphones are compared with currently mined ores.•Fluctuating metal prices can affect recycling efforts.•Potential recycling options and obstacles for metals in smartphones are discussed.
Background: Resource utilisation and direct costs associated with glaucoma progression in Europe are unknown. As population progressively ages, the economic impact of the disease will increase. ...Methods: From a total of 1655 consecutive cases, the records of 194 patients were selected and stratified by disease severity. Record selection was based on diagnoses of primary open angle glaucoma, glaucoma suspect, ocular hypertension, or normal tension glaucoma; 5 years minimum follow up were required. Glaucoma severity was assessed using a six stage glaucoma staging system based on static threshold visual field parameters. Resource utilisation data were abstracted from the charts and unit costs were applied to estimate direct costs to the payer. Resource utilisation and estimated direct cost of treatment, per person year, were calculated. Results: A statistically significant increasing linear trend (p = 0.018) in direct cost as disease severity worsened was demonstrated. The direct cost of treatment increased by an estimated €86 for each incremental step ranging from €455 per person year for stage 0 to €969 per person year for stage 4 disease. Medication costs ranged from 42% to 56% of total direct cost for all stages of disease. Conclusions: These results demonstrate for the first time in Europe that resource utilisation and direct medical costs of glaucoma management increase with worsening disease severity. Based on these findings, managing glaucoma and effectively delaying disease progression would be expected to significantly reduce the economic burden of this disease. These data are relevant to general practitioners and healthcare administrators who have a direct influence on the distribution of resources.
Drug incompatibilities can lead to loss of effectiveness of drugs or to increased risk for undesirable effects that can even be life-threatening. Especially children are at high risk. Databases are ...an important source of information in routine care to avoid incompatibilities. However,
they were supposedly developed considering drugs for use in adults. Thus, we analysed to what extent databases are appropriate for the identification of incompatibilities in intravenous (i.v.) drug therapy in paediatric intensive care. We analysed the information provided by two databases
(Database A and B) on all pairs of two drugs prescribed to be administered via the same i.v. access line in a university paediatric intensive care unit during the study period of 50 days. A total of 50 different i.v. drugs was prescribed in 318 different combinations (drug pairs). We found
information on (in)compatibilities in 23.0 % (73/318) in Database A and in 31.1 % (99/318) in Database B. Only in 11.0 % (35/318) of the drug pairs, both databases provided information. Considering those drug pairs, in 17.1 % (6/35) Database B indicated compatibility whereas Database A indicated
incompatibility. Compatibility information delivered by databases on drugs used in paediatric intensive care is incomplete, heterogeneous, and partly contradictory. Thus, an increased awareness on the strengths and limitations of different databases is necessary to avoid patient harm.
The representation of general distributions or measured data by phase-type distributions is an important and nontrivial task in analytical modeling. Although a large number of different methods for ...fitting parameters of phase-type distributions to data traces exist, many approaches lack efficiency and numerical stability. In this paper, a novel approach is presented that fits a restricted class of phase-type distributions, namely, mixtures of Erlang distributions, to trace data. For the parameter fitting, an algorithm of the expectation maximization type is developed. This paper shows that these choices result in a very efficient and numerically stable approach which yields phase-type approximations for a wide range of data traces that are as good or better than approximations computed with other less efficient and less stable fitting methods. To illustrate the effectiveness of the proposed fitting algorithm, we present comparative results for our approach and two other methods using six benchmark traces and two real traffic traces as well as quantitative results from queuing analysis
Dental visits represent an opportunity to identify and assist patients with unhealthy substance use, but little is known about how dentists are addressing patients' use of tobacco, alcohol and ...illicit drugs. The authors surveyed dentists to learn about the role their practices might play in providing substance-use screening and interventions.
The authors distributed a 41-item Web-based survey to all 210 dentists active in the Practitioners Engaged in Applied Research and Learning Network, a practice-based research network. The questionnaire assessed dental practices' policies and current practices, attitudes and perceived barriers to providing services for tobacco, alcohol and illicit drug use.
One hundred forty-three dentists completed the survey (68 percent response rate). Although screening was common, fewer dentists reported that they were providing follow-up counseling or referrals for substance use. Insufficient knowledge or training was the most frequently cited barrier to intervention. Many dentists reported they would offer assistance for use of tobacco (67 percent) or alcohol or illicit drugs (52 percent) if reimbursed; respondents who treated publicly insured patients were more likely to reply that they would offer this assistance.
Dentists recognize the importance of screening for substance use, but they lack the clinical training and practice-based systems focused on substance use that could facilitate intervention. Practical Implications. The results of this study indicate that dentists may be willing to address substance use among patients, including use of alcohol and illicit drugs in addition to tobacco, if barriers are reduced through changes in reimbursement, education and systems-level support.
Inhomogeneous continuous-time Markov chains play an important role in different application areas. In contrast to homogeneous continuous-time Markov chains, where a large number of numerical analysis ...techniques are available and have been compared, few results about the performance of numerical techniques in the inhomogeneous case are known. This paper presents a new variant of the uniformization technique, the most efficient approach for homogeneous Markov chains. The new uniformization technique allows for the stable computation of strict bounds for the transient distribution of inhomogeneous continuous-time Markov chains, which is not possible with other numerical techniques that provide only an approximation of the distribution and asymptotic bounds. Furthermore, another variant of uniformization is presented that computes an approximation of the transient distribution and is shown to outperform standard differential equation solvers if transition rates change slowly.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The Great Dyke of Zimbabwe constitutes the world's second largest reserve of platinum group elements (PGE) after the Bushveld Complex in neighbouring South Africa. Within the Great Dyke, economic ...concentrations of PGE are restricted to sulphide disseminations of the Main Sulphide Zone (MSZ), which are currently mined at the Ngezi, Unki, and Mimosa mines. Near-surface oxidized MSZ ores have a large potential. Their total resources are in the range of 160-250 Mt; however, all previous attempts to extract the PGE from this ore type have proved uneconomic due to low PGE recoveries (<< 50 per cent) achieved by conventional metallurgical methods. Within the ores of pristine, sulphide-bearing MSZ, the PGE are bimodally distributed. Platinum occurs mainly in the form of discrete platinum group mineral (PGM) grains (mainly bismuthotellurides, sulphides, and arsenides), whereas approximately 80 per cent of the Pd (and some Rh) is hosted in pentlandite. Within the oxidized MSZ ores, the PGE are polymodally distributed. Whereas the arsenide- and sulphide-PGMs that make up approximately 25 per cent of the original Pt content of the ore largely remain stable (relict PGMs), the remaining PGMs are disintegrated. The base metal sulphides are destroyed, partly releasing their base metal and PGE contents, and are replaced by iron oxides or hydroxides. Unspecified amounts of the PGE are redistributed and either form secondary PGMs, are found in chemically and mineralogically ill-defined (Pt/Pd)-oxides or hydroxides, or in iron-hydroxides, Mn-Co-hydroxides, and in secondary silicates. The problematic processing of oxidized MSZ ores is attributable to their complex nature and polymodal distribution of the PGE, prohibiting a significant upgrading of the ores by conventional metallurgical methods. Therefore, only bulk leaching methods are viable for ore treatment, and novel metallurgical methods have to be developed for the processing of these ores. Our ongoing work aims at locating the PGE in their mineralogical form in order to understand the mineralogical balance of the PGE in the ores and thereby facilitate the evaluation of metallurgical options for their recovery. A short overview on options and recent advances regarding the recovery of the PGE from oxidized ores is given.
We have designed an ASIC for use in a parallel optical engine for a new layer of the ATLAS pixel detector in the initial phase of the LHC luminosity upgrade. The ASIC is a 12-channel VCSEL (Vertical ...Cavity Surface Emitting Laser) array driver capable of operating up to 5Gb/s per channel. The ASIC is designed using a 130nm CMOS process to enhance the radiation-hardness. A scheme for redundancy has also been implemented to allow bypassing of a broken VCSEL. The ASIC also contains a power-on reset circuit that sets the ASIC to a default configuration with no signal steering. In addition, the bias and modulation currents of the individual channels are programmable. The performance of the first prototype ASIC up to 5Gb/s is satisfactory. Furthermore, we are able to program the bias and modulation currents and to bypass a broken VCSEL channel. We are currently upgrading our design to allow operation at 10Gb/s per channel yielding an aggregated bandwidth of 120Gb/s. Some preliminary results of the design will be presented.
ABSTRACT
Objective: The purpose of this study was to estimate costs and quality of life (QoL) of late-stage glaucoma patients in 4 European countries.
Methods: Retrospective review of medical charts ...of patients with POAG who were followed in a low-vision or vision rehabilitation center in one of 4 countries for at least 1 year was used to determine patient characteristics, health status, and health care resource use. Visual impairment was measured by best-corrected visual acuity (Snellen score). Patients were also interviewed over the telephone in order to assess their health-related QoL (using EuroQol EQ-5D) and use of resources including: the number of visits to rehabilitation centers, visits to hospital and non-hospital specialists, the use of low-vision devices, medication, tests, and the use of hired home help. The costs associated with resource use were calculated from the perspective of a third-party payer of health and social care based on resource usage and unit costs in each country.
Results: Patients undergoing visual rehabilitation in France (n = 21), Denmark (n = 59), Germany (n = 60), and the United Kingdom (n = 22) were identified, interviewed and had their medical charts reviewed. Annual maintenance costs of late-stage glaucoma amounted to €830 ( ± 445) on average. Average home help costs were more than 3 times higher. QoL, on average, was 0.65 ( ± 0.28). QoL was positively correlated with the level of visual acuity in the patients' best eye. On the other hand, visual acuity was also positively correlated to health care costs, but negatively correlated to costs of home help.
Conclusions: The study was limited by its observational, uncontrolled design. The finding that late-stage glaucoma is associated with higher home help costs than health care maintenance costs suggests that potential savings from a better preventive treatment are to be found for social care payers rather than health care payers.
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