Potassium and Cesium Ion Selectivity in Relation to Clay Mineral Structure

Abstract- Selectivity of a number of vermiculites, montmorillonites and micas for K and Cs ions was determined by sorption of these ions from equilibrium solutions of diverse concentrations. The selec-tivity coefficients were related to the layer charge density and the area of the frayed edges in layer silicates. Montmorillonites had the smallest selectivity for the two ions, while biotite and illite had the great-est selectivity. Selectivity of biotite and illite was limited to small concentrations of K, however. At greater concentrations the selectivity of vermiculite for K exceeded the selectivity of the micas. The greater selectivity of vermiculites than montmorillonites for K and Cs ions was attributed to the greater layer charge density in vermiculites. The greater selectivity of micas than montmorillonites and vermiculites was attributed to the frayed edges of micas in addition to their larger layer charge density. As the frayed edRes in illite were increased inarea by removal of the interlayer K, the selec-tivity of illite for K also increased; thus confirming the selectivity of frayed edges for the K ions

Adoption of BIM by architectural firms in India: technology–organization–environment perspective

Building information modelling (BIM) is being heralded as a remarkable innovation in the built environment sector with expectations of lofty sector-wide improvements. Some countries have shown remarkable levels of uptake of BIM, along the way documenting some evidence of benefits stemming from BIM. However, countries such as India and China are late entrants in the BIM adoption journey and are seeing a slower adoption rate. This study develops a model using the technology–organization–environment framework to study the factors influencing BIM adoption by architectural firms in India and reasons for this slow adoption. The proposed model of BIM adoption is tested using the partial least square method against responses collected from 184 industry professionals based in India. Findings reveal that the adoption of BIM by Indian architectural firms is at the ‘experimentation’ stage with variables such as expertise, trialability, and management support exhibiting a strong positive influence on BIM adoption. The study also explains the status of BIM adoption in India with the help of a multi-level social construct, which places the level of BIM adoption in India between the micro- and meso-levels of organizational scales. Similarities and dissimilarities with previous findings are discussed in the paper to highlight the findings of this study. © 2016 Informa UK Limited, trading as Taylor & Francis Grou

Moving from a Product-Based Economy to a Service-Based Economy for a More Sustainable Future

Traditionally, economic growth and prosperity have been linked with the availability, production and distribution of tangible goods as well as the ability of consumers to acquire such goods. Early evidence regarding this connection dates back to Adam Smith's Wealth of Nations (1776), in which any activity not resulting in the production of a tangible good is characterized as unproductive of any value." Since then, this coupling of economic value and material production has been prevalent in both developed and developing economies throughout the world. One unintended consequence of this coupling has been the exponential increase in the amount of solid waste being generated. The reason is that any production and consumption of material goods eventually generates the equivalent amount of (or even more) waste. Exacerbating this problem is the fact that, with today's manufacturing and supply chain management technologies, it has become cheaper to dispose and replace most products rather than to repair and reuse them. This has given rise to what some call a disposable society." To put things in perspective: In 2012 households in the U.K. generated approximately 22 thousand tons of waste, which amounted to 411 kg of waste generated per person (Department for Environment, Food & Rural Affairs, 2015). During the same time period, households in the U.S. generated 251 million tons of waste, which is equivalent to a person generating approximately 2 kg of waste every day (U.S. Environmental Protection Agency, 2012). Out of these 251 million tons of total waste generated, approximately 20% of the discarded items were categorized as durable goods. The disposal of durable goods is particularly worrisome because they are typically produced using material from non- renewable resources such as iron, minerals, and petroleum-based raw materials

Abdominal aortic aneurysm repair with the Zenith stent graft: Short to midterm results

AbstractPurpose: The purpose of this study was to assess the short-term and mid-term results of endovascular aneurysm repair with the Zenith stent graft in a single-center prospective study. Method: Between October 1998 and July 2001, we used the Zenith stent graft for elective endovascular aneurysm repair in 116 patients, six of whom were women. The mean age was 75 years, and the mean aneurysm diameter was 60.3 ± 8.8 mm. Stent grafts were oversized 10% to 20% relative to computed tomographic (CT) scan-based diameter measurements. All repairs were performed in the operating room through surgically exposed femoral arteries. The results were assessed before discharge with three-phase, contrast-enhanced CT scan and plain abdominal radiograph. These studies were repeated at 1, 6, 12, and 24 months after operation. Follow-up periods ranged from 1 to 34 months. Results: No failed insertions and no conversions to open surgery occurred. The diameter of the main body of the stent graft was 28 mm or more in 73 patients (63%). Additional stents were inserted during surgery to treat kinking in eight patients (6.9%) and renal artery encroachment in two patients (1.7%). Mean fluoroscopy time was 35.1 ± 18.3 minutes, contrast load was 146 ± 53 mL (350 mg/mL), and estimated blood loss was 249 ± 407 mL. The major complication rate was 9.5%, and the minor complication rate was 10.3%. The perioperative complications were myocardial infarction in four patients, arrythmia in four patients, and pulmonary embolism, renal failure, stroke, small bowel obstruction, femoral stenosis, digital embolism, and graft limb thrombosis in one patient each. All 116 patients went home from the hospital, but one patient died 2 weeks later of a combination of pulmonary embolism and myocardial infarction. Endoleak was seen on the first CT scan in 16 patients (15%); 15 were type II, and one was type III. No endoleaks of type I or IV were seen. Additional interventions were performed for each of the following conditions: type II endoleak (n = 4), type III endoleak (n = 1), femoral clamp injury (n = 1), renal artery stenosis (n = 1), and graft limb occlusion (n = 1). One patient had acute aneurysm dilatation and rupture caused by a type II endoleak through the inferior mesenteric artery 6 months after stent graft implantation. No cases were seen of late graft occlusion, stent graft migration, stent fracture, barb fracture, or secondary endoleak. Conclusion: The Zenith device is safe, versatile, and effective in the short to medium term. Most patients need wide stent grafts (≥28 mm proximally and ≥16 mm distally) to achieve 10% to 20% oversizing to prevent type I endoleak. (J Vasc Surg 2002;36:217-25.

Endoleak after endovascular repair of abdominal aortic aneurysm

AbstractPurpose: We sought to assess the role of endovascular techniques in the management of perigraft flow (endoleak) after endovascular repair of an abdominal aortic aneurysm. Method: We performed endovascular repair of abdominal aortic aneurysm in 114 patients, using a variety of Gianturco Z-stent–based prostheses. Results were evaluated with contrast-enhanced computed tomography (CT) at 3 days, 3 months, 6 months, 12 months, and every year after the operation. An endoleak that occurred 3 days after operation led to repeat CT scanning at 2 weeks, followed by angiography and attempted endovascular treatment. Results: Endoleak was seen on the first postoperative CT scan in 21 (18%) patients and was still present at 2 weeks in 14 (12%). On the basis of angiographic localization of the inflow, the endoleak was pure type I in 3 cases, pure type II in 9, and mixed-pattern in 2. Of the 5 type I endoleaks, 3 were proximal and 2 were distal. All five resolved after endovascular implantation of additional stent-grafts, stents, and embolization coils. Although inferior mesenteric artery embolization was successful in 6 of 7 cases and lumbar embolization was successful in 4 of 7, only 1 of 11 primary type II endoleaks was shown to be resolved on CT scanning. There were no type III or type IV endoleaks (through the stent-graft). Endoleak was associated with aneurysm dilation two cases. In both cases, the aneurysm diameter stabilized after coil embolization of the inferior mesenteric artery. There were two secondary (delayed) endoleaks; one type I and one type II. The secondary type I endoleak and the associated aneurysm rupture were treated by use of an additional stent-graft. The secondary type II endoleak was not treated. Conclusions: Type I endoleaks represent a persistent risk of aneurysm rupture and should be treated promptly by endovascular means. Type II leaks are less dangerous and more difficult to treat, but coil embolization of feeding arteries may be warranted when leakage is associated with aneurysm enlargement. (J Vasc Surg 2001;34:98-105.

Caesium incorporation and retention in illite interlayers

Radioactive caesium (chiefly 137Cs) is a major environmental pollutant. The mobility of Cs in temperate soils is primarily controlled by sorption onto clay minerals, particularly the frayed edges of illite interlayers. This paper investigates the adsorption of Cs to illite at the molecular scale, over both the short and long term. Transmission electron microscopy (TEM) images showed that after initial absorption into the frayed edges, Cs migrated into the illite interlayer becoming incorporated within the mineral structure. Caesium initially exchanged with hydrated Ca at the frayed edges, causing them to collapse. This process was irreversible as Cs held in the collapsed interlayers was not exchangeable with Ca. Over the long term Cs did not remain at the edge of the illite crystals, but diffused into the interlayers by exchange with K. Results from extended X-ray absorption fine structure spectroscopy (EXAFS) and density functional theory modelling confirmed that Cs was incorporated into the illite interlayer and revealed its bonding environment

Investigations into the impact of locally modified sensor architectures on the detection efficiency of silicon micro-strip sensors

The High Luminosity Upgrade of the LHC will require the replacement of the Inner Detector of ATLAS with the Inner Tracker (ITk) in order to cope with higher radiation levels and higher track densities. Prototype silicon strip detector modules are currently developed and their performance is studied in both particle test beams and X-ray beams. In previous test beam measurements of prototype modules, the response of silicon sensors has been studied in detailed scans across individual sensor strips. These scans found instances of sensor strips collecting charge across areas on the sensor deviating from the geometrical width of a sensor strip. The variations have been linked to local features of the sensor architecture. This paper presents results of detailed sensor measurements in both X-ray and particle beams investigating the impact of sensor features (metal pads and p-stops) on the sensor strip response

Characterisation of strip silicon detectors for the ATLAS Phase-II Upgrade with a micro-focused X-ray beam

The planned HL-LHC (High Luminosity LHC) in 2025 is being designed to maximise the physics potential through a sizable increase in the luminosity up to 6 · 1034 cm−2 s −1 . A consequence of this increased luminosity is the expected radiation damage at 3000 fb−1 after ten years of operation, requiring the tracking detectors to withstand fluences to over 1 · 1016 1 MeV neq/cm2 . In order to cope with the consequent increased readout rates, a complete re-design of the current ATLAS Inner Detector (ID) is being developed as the Inner Tracker (ITk). Two proposed detectors for the ATLAS strip tracker region of the ITk were characterized at the Diamond Light Source with a 3 µm FWHM 15 keV micro focused X-ray beam. The devices under test were a 320 µm thick silicon stereo (Barrel) ATLAS12 strip mini sensor wire bonded to a 130 nm CMOS binary readout chip (ABC130) and a 320 µm thick full size radial (end-cap) strip sensor - utilizing bi-metal readout layers - wire bonded to 250 nm CMOS binary readout chips (ABCN-25). A resolution better than the inter strip pitch of the 74.5 µm strips was achieved for both detectors. The effect of the p-stop diffusion layers between strips was investigated in detail for the wire bond pad regions. Inter strip charge collection measurements indicate that the effective width of the strip on the silicon sensors is determined by p-stop regions between the strips rather than the strip pitch

Differences sustained between diffuse and limited forms of juvenile systemic sclerosis in expanded international cohort. www.juvenile-scleroderma.com

OBJECTIVES: To evaluate the baseline clinical characteristics of juvenile systemic sclerosis (jSSc) patients in the international Juvenile SSc Inception Cohort (jSScC), compare these characteristics between the classically defined diffuse (dcjSSc) and limited cutaneous (lcjSSc) subtypes, and among those with overlap features. METHODS: A cross-sectional study was performed using baseline visit data. Demographic, organ system evaluation, treatment, and patient and physician reported outcomes were extracted and summary statistics applied. Comparisons between dcjSSc and lcSSc subtypes and patients with and without overlap features were performed using Chi-square and Mann Whitney U-tests. RESULTS: At data extraction 150 jSSc patients were enrolled across 42 centers, 83% were Caucasian, 80% female, dcjSSc predominated (72%), and 17% of the cohort had overlap features. Significant differences were found between dcjSSc and lcjSSc regarding the modified Rodnan Skin Score, presence of Gottron's papules, digital tip ulceration, 6 Minute walk test, composite pulmonary and cardiac involvement. All more frequent in dcSSc except for cardiac involvement. DcjSSc patients had significantly worse scores for physician rated disease activity and damage. A significantly higher occurrence of Gottron's papules, musculoskeletal involvement and composite pulmonary involvement, and significantly lower frequency of Raynaud's phenomenon, were seen in those with overlap features. CONCLUSION: Results from a large international jSSc cohort demonstrate significant differences between dcjSSc and lcjSSc patients including more globally severe disease and increased frequency of ILD in dcjSSc patients, while those with lcSSc have more frequent cardiac involvement. Those with overlap features had an unexpected higher frequency of interstitial lung disease