Modification of Ca-Montmorillonite by Low-Temperature Heat Treatment, HR-106, 1964

Objectives of this investigation were to measure the effects of moderate heat treatments (below the dehydroxylation temperature) on physical and chemical properties of a calcium-montmorillonite clay. Previous workers have noted the reduction in cation exchange capacity and swelling property after heating in the range 200 to 400°C, and have suggested several possible explanations, such as hysteresis effect, increased inter-layer attractions due to removal of inter-layer water, or changes in the disposition of inter-layer or layer surface ions. The liquid limits of Ca-montmorillonite were steadily decreased with increased temperature of treatment, levelling at about 450°C. The plastic limit decreased slightly up to 350°C, above which samples could no longer be rolled into threads. The gradual change is in contrast with sudden major changes noted for weight loss (maximum rates of change at l00°C and 500°C), glycol retention surface area (520°C), and d001 diffraction peak intensity (17.7 A spacing) and breadth after glycolation (530°C). Other properties showing more gradual reductions with heat treatment were amount of exchangeable calcium (without water soaking), cation exchange capacity by NH4AC method, and d001 intensity (21 A spacing) after storing at 100% r.h. one month and re-wetting with water. Previous water soaking allowed much greater release of fixed Ca++ up to 450°C. Similar results were obtained with cation exchange capacities when samples were treated with N CaCl2 solution. The 21.0 A peak intensity curve showed close similarity to the liquid limit and plastic index curves in the low temperature range, and an explanation is suggested.

Investigation of Two Bridge Alternatives for Low Volume Roads Volume 2 of 2 Concept 2: Beam In Slab Bridge, HR-382, 1997

Recent reports have indicated that 23.5% of the nation's highway bridges are structurally deficient and 17.7% are functionally obsolete. A significant number of these bridges are on the Iowa secondary road system where over 86% of the rural bridge management responsibilities are assigned to the counties. Some of the bridges can be strengthened or otherwise rehabilitated, but many more are in need of immediate replacement. In a recent investigation (HR-365 "Evaluation of Bridge Replacement Alternatives for the County Bridge System") several types of replacement bridges that are currently being used on low volume roads were identified. It was also determined that a large number of counties (69%) have the ability and are interested in utilizing their own forces to design and construct short span bridges. After reviewing the results from HR-365, the research team developed one "new" bridge replacement concept and a modification of a replacement system currently being used. Both of these bridge replacement alternatives were investigated in this study, the results of which are presented in two volumes. This volume (Volume 2) presents the results of Concept 2 - Modification of the Beam-in-Slab Bridge. Concept 1 - Steel Beam Precast Units is presented in Volume 1. Concept 2 involves various laboratory tests of the Beam-in-Slab bridge (BISB) currently being used by Benton County and several other Iowa counties. In this investigation, the behavior and strength of the BISB were determined; a new method of obtaining composite action between the steel beams and concrete was also tested. Since the Concept 2 bridge is primarily intended for use on low-volume roads, the system can be constructed with new or used beams. In the experimental part of the investigation, there were three types of laboratory tests: push-out tests, service and ultimate load tests of models of the BISB, and composite beam tests utilizing the newly developed shear connection. In addition to the laboratory tests, there was a field test in which an existing BISB was service load tested. An equation was developed for predicting the strength of the shear connection investigated; in addition, a finite element model for analyzing the BISB was also developed. Push-out tests were completed to determine the strength of the recently developed shear connector. A total of 36 specimens were tested, with variables such as hole diameter, hole spacing, presence of reinforcement, etc. being investigated. In the model tests of the BISB, two and four beam specimens [L=9,140 mm (30 ft)] were service load tested for behavior and load distribution data. Upon completion of these tests, both specimens were loaded to failure. In the composite beam tests, four beams, one with standard shear studs and three using the shear connection developed, were tested. Upon completion of the service load tests, all four beams were loaded to failure. The strength and behavior of the beams with the new shear connection were found to be essentially the same as that of the specimen with standard shear studs.

Non-Grouted Bonded PCC Overlay City of Oskaloosa, HR-528, 1993

Based upon the success the Iowa Department of Transportation has had using thin bonded, low slump, dense portland cement concrete on bridge decks for rehabilitation, it was decided to pursue research in the area of bonded portland cement concrete resurfacing of pavements. Since that time, in an effort to reduce costs, research was conducted into eliminating the grouting operation. On this project a non-grouted overlay was used to modernize an existing urban street. This research project is located in the City of Oskaloosa on 11th Avenue from South M Street to South Market Street. Construction of the project went well and the non-grouted overlay has performed very well to date.

Reinforced Slope with Geogrids, HR-548, 1997

The objective of this research study is to evaluate the performance, maintenance requirements and cost effectiveness of constructing reinforced slope along a concrete bikeway overpass with a Geogrid system such as manufactured by Tensar Corporation or Reinforced Earth Company. This final report consists of two separate reports - construction and performance. An earlier design report and work plan was submitted to the Iowa DOT in 1989. From the Design Report, it was determined that the reinforced slope would be the most economical system for this particular bikeway project. Preliminary cost estimates for other design alternatives including concrete retaining walls, gabions and sheet pile walls ranged from $204/L.F. to $220/L.F. The actual final construction cost of the reinforced slope with GEDGRIDS was around $112/L.F. Although, since the reinforced slope system was not feasible next to the bridge overpass because of design constraints, a fair cost comparison should reflect costs of constructing a concrete retaining wall. Including the concrete retaining wall costs raises the per lineal foot cost to around $122/L.F. In addition to this initial construction cost effectiveness of the reinforced slope, there has been little or no maintenance needed for this reinforced slope. It was noted that some edge mowing or weed whacking could be done near the concrete bikeway slab to improve the visual quality of the slope, but no work has been assigned to city crews. It was added that this kind of weed whacking over such steep slope is more difficult and there could possibly be more potential for work related injury. The geogrid reinforced slope has performed really well once the vegetation took control and prevented soil washing across the bikeway slab. To that end, interim erosion control measures might need to be considered in future projects. Some construction observations were noted. First, there i s no specialized experience or equipment required for a contractor to successfully build a low-to-medium geogrid reinforced slope structure. Second, the adaptability of the reinforced earth structure enables the designer to best fit the shape of the structure to the environment and could enhance aesthetic quality. Finally, a reinforced slope can be built with relatively soft soils provided differential settlements between facing are limited to one or two percent.

Low-cost microprocessed instrument for evaluating soil temperature profile

This paper describes a low-cost microprocessed instrument for in situ evaluating soil temperature profile ranging from -20.0°C to 99.9°C, and recording soil temperature data at eight depths from 2 to 128 cm. Of great importance in agriculture, soil temperature affects plant growth directly, and nutrient uptake as well as indirectly in soil water and gas flow, soil structure and nutrient availability. The developed instrument has potential applications in the soil science, when temperature monitoring is required. Results show that the instrument with its individual sensors guarantees ±0.25°C accuracy and 0.1°C resolution, making possible localized management changes within decision support systems. The instrument, based on complementary metal oxide semiconductor devices as well as thermocouples, operates in either automatic or non-automatic mode.

Low Permeability of Concrete for Bridge Deck Overlay, MLR-89-1, 1993

The penetration of chloride ions from deicing salts into the portland cement concrete of bridge decks can cause corrosion and serious damage to the reinforcing steel. Concrete properties which prevent chloride penetration into the bridge deck and provide a good structural and economic wearing surface are desirable. A variety of mix designs have been tried in the past in search of improved performance and lower costs for bridge deck overlay concrete. A group of mixes with various designs have been tested in this project and results are being compared to determine which concrete mix appears to be the most cost effective and resistant to chloride penetration for bridge deck overlay use.

Investigation of Two Bridge Alternatives for Low Volume Roads - Phase II Volume 2 of 2, Concept 2: Beam in Slab Bridge, TR-410, 2000

This project continues the research which addresses the numerous bridge problems on the Iowa secondary road system. It is a continuation (Phase 2) of Project HR-382, in which two replacement alternatives (Concept 1: Steel Beam Precast Units and Concept 2: Modification of the Benton County Beam-in-Slab Bridge) were investigated. In previous research for concept 1, a precast unit bridge was developed through laboratory testing. The steel-beam precast unit bridge requires the fabrication of precast double-tee (PCDT) units, each consisting of two steel beams connected by a reinforced concrete deck. The weight of each PCDT unit is minimized by limiting the deck thickness to 4 in., which permits the units to be constructed off-site and then transported to the bridge site. The number of units required is a function of the width of bridge desired. Once the PCDT units are connected, a cast-in-place reinforced concrete deck is cast over the PCDT units and the bridge railing attached. Since the steel beam PCDT unit bridge design is intended primarily for use on low-volume roads, used steel beams can be utilized for a significant cost savings. In previous research for concept 2, an alternate shear connector (ASC) was developed and subjected to static loading. In this investigation, the ASC was subjected to cyclic loading in both pushout specimens and composite beam tests. Based on these tests, the fatigue strength of the ASC was determined to be significantly greater than that required in typical low volume road single span bridges. Based upon the construction and service load testing, the steel-beam precast unit bridge was successfully shown to be a viable low volume road bridge alternative. The construction process utilized standard methods resulting in a simple system that can be completed with a limited staff. Results from the service load tests indicated adequate strength for all legal loads. An inspection of the bridge one year after its construction revealed no change in the bridge's performance. Each of the systems previously described are relatively easy to construct. Use of the ASC rather than the welded studs significantly simplified the work, equipment, and materials required to develop composite action between the steel beams and the concrete deck.

Evaluation of Gateway and Low-Cost Traffic-Calming Treatments for Major Routes in Small, Rural Communities, TR-523, 2007

Many rural communities have developed around highways or major county roads; as a result, the main street through small rural communities is often part of a high-speed rural highway. Highways and county roads are characterized by high speeds outside the city limits; they then transition into a reduced speed section through the rural community. Consequently, drivers passing through the community often enter at high speeds and maintain those speeds as they travel through the community. Traffic calming in small rural communities along major roadways is common in Europe, but the U.S. does not have experience with applying traffic-calming measures outside of major urban areas. The purpose of the project was to evaluate traffic-calming treatments on the major road through small Iowa communities using either single-measure low-cost or gateway treatments. The project was partially funded by the Iowa Highway Research Board (IHRB). The focus of the IHRB portion was to evaluate single-measure, low-cost, traffic-calming measures that are appropriate to major roads through small rural communities. Seven different low-cost traffic treatments were implemented and evaluated in five rural Iowa communities. The research evaluated the use of two gateway treatments in Union and Roland; five single-measure treatments (speed table, on-pavement “SLOW” markings, a driver speed feedback sign, tubular markers, and on-pavement entrance treatments) were evaluated in Gilbert, Slater, and Dexter.

The cost effectiveness of pharmacological smoking cessation therapies in developing countries: a case study in the Seychelles

OBJECTIVE: To examine the incremental cost effectiveness of the five first line pharmacological smoking cessation therapies in the Seychelles and other developing countries. DESIGN: A Markov chain cohort simulation. SUBJECTS: Two simulated cohorts of smokers: (1) a reference cohort given physician counselling only; (2) a treatment cohort given counselling plus cessation therapy. INTERVENTION: Addition of each of the five pharmacological cessation therapies to physician provided smoking cessation counselling. MAIN OUTCOME MEASURES: Cost per life-year saved (LYS) associated with the five pharmacotherapies. Effectiveness expressed as odds ratios for quitting associated with pharmacotherapies. Costs based on the additional physician time required and retail prices of the medications. RESULTS: Based on prices for currently available generic medications on the global market, the incremental cost per LYS for a 45 year old in the Seychelles was 599 US dollars for gum and 227 dollars for bupropion. Assuming US treatment prices as a conservative estimate, the incremental cost per LYS was significantly higher, though still favourable in comparison to other common medical interventions: 3712 dollars for nicotine gum, 1982 dollars for nicotine patch, 4597 dollars for nicotine spray, 4291 dollars for nicotine inhaler, and 1324 dollars for bupropion. Cost per LYS increased significantly upon application of higher discount rates, which may be used to reflect relatively high opportunity costs for health expenditures in developing countries with highly constrained resources and high overall mortality. CONCLUSION: Pharmacological cessation therapy can be highly cost effective as compared to other common medical interventions in low mortality, middle income countries, particularly if medications can be procured at low prices.

Treating Iowa's Marginal Aggregates and Soils by Foamix Process, HR-212, 1980

Quality granular materials suitable for building all-weather roads are not uniformly distributed throughout the state of Iowa. For this reason the Iowa Highway Research Board has sponsored a number of research programs for the purpose of developing new and effective methods for making use of whatever materials are locally available. This need is ever more pressing today due to the decreasing availability of road funds and quality materials, and the increasing costs of energy and all types of binder materials. In the 1950s, Professor L. H. Csanyi of Iowa State University had demonstrated both in the laboratory and in the field, in Iowa and in a number of foreign countries, the effectiveness of preparing low cost mixes by stabilizing ungraded local aggregates such as gravel, sand and loess with asphalt cements using the foamed asphalt process. In this process controlled foam was produced by introducing saturated steam at about 40 psi into heated asphalt cement at about 25 psi through a specially designed and properly adjusted nozzle. The reduced viscosity and the increased volume and surface energy in the foamed asphalt allowed intimate coating and mixing of cold, wet aggregates or soils. Through the use of asphalt cements in a foamed state, materials normally considered unsuitable could be used in the preparation of mixes for stabilized bases and surfaces for low traffic road construction. By attaching the desired number of foam nozzles, the foamed asphalt can be used in conjunction with any type of mixing plant, either stationary or mobile, batch or continuous, central plant or in-place soil stabilization.

Combination of lentivector immunization and low-dose chemotherapy or PD-1/PD-L1 blocking primes self-reactive T cells and induces anti-tumor immunity.

In the last two decades, anti-cancer vaccines have yielded disappointing clinical results despite the fact that high numbers of self/tumor-specific T cells can be elicited in immunized patients. Understanding the reasons behind this lack of efficacy is critical in order to design better treatment regimes. Recombinant lentivectors (rLVs) have been successfully used to induce antigen-specific T cells to foreign or mutated tumor antigens. Here, we show that rLV expressing a murine nonmutated self/tumor antigen efficiently primes large numbers of self/tumor-specific CD8(+) T cells. In spite of the large number of tumor-specific T cells, however, no anti-tumor activity could be measured in a therapeutic setting, in mice vaccinated with rLV. Accumulating evidence shows that, in the presence of malignancies, inhibition of T-cell activity may predominate overstimulation. Analysis of tumor-infiltrating lymphocytes revealed that specific anti-tumor CD8(+) T cells fail to produce cytokines and express high levels of inhibitory receptors such as programmed death (PD)-1. Association of active immunization with chemotherapy or antibodies that block inhibitory pathways often leads to better anti-tumor effects. We show here that combining rLV vaccination with either cyclophosphamide or PD-1 and PD-L1 blocking antibodies enhances rLV vaccination efficacy and improves anti-tumor immunity.

What can we learn from international comparisons of costs by DRG ?

OBJECTIVES: The objective of this study was to compare costs data by diagnosis related group (DRG) between Belgium and Switzerland. Our hypotheses were that differences between countries can probably be explained by methodological differences in cost calculations, by differences in medical practices and by differences in cost structures within the two countries. METHODS: Classifications of DRG used in the two countries differ (AP-DRGs version 1.7 in Switzerland and APR-DRGs version 15.0 in Belgium). The first step of this study was to transform Belgian summaries into Swiss AP-DRGs. Belgian and Swiss data were calculated with a clinical costing methodology (full costing). Belgian and Swiss costs were converted into US$ PPP (purchasing power parity) in order to neutralize differences in purchasing power between countries. RESULTS: The results of this study showed higher costs in Switzerland despite standardization of cost data according to PPP. The difference is not explained by the case-mix index because this was similar for inliers between the two countries. The length of stay (LOS) was also quite similar for inliers between the two countries. The case-mix index was, however, higher for high outliers in Belgium, as reflected in a higher LOS for these patients. Higher costs in Switzerland are thus probably explained mainly by the higher number of agency staff by service in this country or because of differences in medical practices. CONCLUSIONS: It is possible to make international comparisons but only if there is standardization of the case-mix between countries and only if comparable accountancy methodologies are used. Harmonization of DRGs groups, nomenclature and accountancy is thus required.

Development of Railroad Highway Grade Crossing Consolidation Rating Formula, 2015

The goal of this project was to provide an objective methodology to support public agencies and railroads in making decisions related to consolidation of at-grade rail-highway crossings. The project team developed a weighted-index method and accompanying Microsoft Excel spreadsheet based tool to help evaluate and prioritize all public highway-rail grade crossings systematically from a possible consolidation impact perspective. Factors identified by stakeholders as critical were traffic volume, heavy-truck traffic volume, proximity to emergency medical services, proximity to schools, road system, and out-of-distance travel. Given the inherent differences between urban and rural locations, factors were considered, and weighted, differently, based on crossing location. Application of a weighted-index method allowed for all factors of interest to be included and for these factors to be ranked independently, as well as weighted according to stakeholder priorities, to create a single index. If priorities change, this approach also allows for factors and weights to be adjusted. The prioritization generated by this approach may be used to convey the need and opportunity for crossing consolidation to decision makers and stakeholders. It may also be used to quickly investigate the feasibility of a possible consolidation. Independently computed crossing risk and relative impact of consolidation may be integrated and compared to develop the most appropriate treatment strategies or alternatives for a highway-rail grade crossing. A crossing with limited- or low-consolidation impact but a high safety risk may be a prime candidate for consolidation. Similarly, a crossing with potentially high-consolidation impact as well as high risk may be an excellent candidate for crossing improvements or grade separation. The results of the highway-rail grade crossing prioritization represent a consistent and quantitative, yet preliminary, assessment. The results may serve as the foundation for more rigorous or detailed analysis and feasibility studies. Other pertinent site-specific factors, such as safety, maintenance costs, economic impacts, and location-specific access and characteristics should be considered.

Cost-effectiveness of surgery in low- and middle-income countries: a systematic review.

BACKGROUND: There is increasing interest in provision of essential surgical care as part of public health policy in low- and middle-income countries (LMIC). Relatively simple interventions have been shown to prevent death and disability. We reviewed the published literature to examine the cost-effectiveness of simple surgical interventions which could be made available at any district hospital, and compared these to standard public health interventions. METHODS: PubMed and EMBASE were searched using single and combinations of the search terms "disability adjusted life year" (DALY), "quality adjusted life year," "cost-effectiveness," and "surgery." Articles were included if they detailed the cost-effectiveness of a surgical intervention of relevance to a LMIC, which could be made available at any district hospital. Suitable articles with both cost and effectiveness data were identified and, where possible, data were extrapolated to enable comparison across studies. RESULTS: Twenty-seven articles met our inclusion criteria, representing 64 LMIC over 16 years of study. Interventions that were found to be cost-effective included cataract surgery (cost/DALY averted range US$5.06-$106.00), elective inguinal hernia repair (cost/DALY averted range US$12.88-$78.18), male circumcision (cost/DALY averted range US$7.38-$319.29), emergency cesarean section (cost/DALY averted range US$18-$3,462.00), and cleft lip and palate repair (cost/DALY averted range US$15.44-$96.04). A small district hospital with basic surgical services was also found to be highly cost-effective (cost/DALY averted 1 US$0.93), as were larger hospitals offering emergency and trauma surgery (cost/DALY averted US$32.78-$223.00). This compares favorably with other standard public health interventions, such as oral rehydration therapy (US$1,062.00), vitamin A supplementation (US$6.00-$12.00), breast feeding promotion (US$930.00), and highly active anti-retroviral therapy for HIV (US$922.00). CONCLUSIONS: Simple surgical interventions that are life-saving and disability-preventing should be considered as part of public health policy in LMIC. We recommend an investment in surgical care and its integration with other public health measures at the district hospital level, rather than investment in single disease strategies.

Referral from primary care to a physical activity programme: establishing long-term adherence? A randomized controlled trial. Rationale and study design

Background: Declining physical activity is associated with a rising burden of global disease. There is little evidence about effective ways to increase adherence to physical activity. Therefore, interventions are needed that produce sustained increases in adherence to physical activity and are cost-effective. The purpose is to assess the effectiveness of a primary care physical activity intervention in increasing adherence to physical activity in the general population seen in primary care. Method and design: Randomized controlled trial with systematic random sampling. A total of 424 subjects of both sexes will participate; all will be over the age of 18 with a low level of physical activity (according to the International Physical Activity Questionnaire, IPAQ), self-employed and from 9 Primary Healthcare Centres (PHC). They will volunteer to participate in a physical activity programme during 3 months (24 sessions; 2 sessions a week, 60 minutes per session). Participants from each PHC will be randomly allocated to an intervention (IG) and control group (CG). The following parameters will be assessed pre and post intervention in both groups: (1) health-related quality of life (SF-12), (2) physical activity stage of change (Prochaska's stages of change), (3) level of physical activity (IPAQ-short version), (4) change in perception of health (vignettes from the Cooperative World Organization of National Colleges, Academies, and Academic Associations of Family Physicians, COOP/WONCA), (5) level of social support for the physical activity practice (Social Support for Physical Activity Scale, SSPAS), and (6) control based on analysis (HDL, LDL and glycated haemoglobin).Participants' frequency of visits to the PHC will be registered over the six months before and after the programme. There will be a follow up in a face to face interview three, six and twelve months after the programme, with the reduced version of IPAQ, SF-12, SSPAS, and Prochaska's stages. Discussion: The pilot study showed the effectiveness of an enhanced low-cost, evidence-based intervention in increased physical activity and improved social support. If successful in demonstrating long-term improvements, this randomised controlled trial will be the first sustainable physical activity intervention based in primary care in our country to demonstrate longterm adherence to physical activity. Trial Registration: A service of the U.S. National Institutes of Health. Developed by the National Library of Medicine. ClinicalTrials.gov ID: NCT00714831.