Summary A systematic review of the literature was performed to evaluate the role of exercise in treating rotator cuff impingement and to synthesize a standard evidence-based rehabilitation protocol. ...Eleven randomized, controlled trials (level 1 and 2) evaluating the effect of exercise in the treatment of impingement were identified. Data regarding demographics, methodology, and outcomes of pain, range of motion, strength, and function were recorded. Individual components of each rehabilitation program were catalogued. Effectiveness was determined by statistical and clinical significance. Although many articles had methodologic concerns, the data demonstrate that exercise has statistically and clinically significant effects on pain reduction and improving function, but not on range of motion or strength. Manual therapy augments the effects of exercise, yet supervised exercise was not different than home exercise programs. Information regarding specific components of the exercise programs was synthesized into a gold standard rehabilitation protocol for future studies on the nonoperative treatment of rotator cuff impingement.
Throwing with high velocity requires extremes of glenohumeral external rotation of the abducted arm where particularly high forces in the shoulder and elbow are endured. Repeated throwing leads to ...dominant-arm bony remodeling of the humerus, glenoid, and elbow, and multiple soft tissue changes that would be considered abnormal. Many of these features are thought to be adaptive and protective. The purpose of this work is to (1) define the concept of adaptive pathology; (2) review the mechanics of the throwing motion; (3) review pertinent physical examination and imaging findings seen in asymptomatic throwers’ shoulders and elbows and describe how these changes develop and may be adaptive—allowing the thrower to perform at high levels; and then (4) review the principles of surgical treatment in the throwing athletes, which should focus on reducing symptoms, but not necessarily restoring the thrower’s anatomy to normal.
Current society is inherently based on liquid hydrocarbon fuel economies and seems to be so for the foreseeable future. Due to the low rates (photocatalysis) and high capital investments ...(solar-thermo-chemical cycles) of competing technologies, reverse water gas shift (rWGS) catalysis appears as the prominent technology for converting CO
2
to CO, which can then be converted
via
CO hydrogenation to a liquid fuel of choice (diesel, gasoline, and alcohols). This approach has the advantage of high rates, selectivity, and technological readiness, but requires renewable hydrogen generation from direct (photocatalysis) or indirect (electricity and electrolysis) sources. The goal of this review is to examine the literature on rWGS catalyst types, catalyst mechanisms, and the implications of their use CO
2
conversion processes in the future.
The reverse water gas shift reaction, its proposed mechanisms, currently used and proposed catalysts and an intensified version of the reaction are evaluated for their abilities to significantly reduced CO
2
atmospheric concentration.
Interest in novel uses of biogas has increased recently due to concerns about climate change and greater emphasis on renewable energy sources. Although biogas is frequently used in low-value ...applications such as heating and fuel in engines or even just flared, reforming is an emerging strategy for converting biogas to syngas, which could then be used to obtain high-value-added liquid fuels and chemicals. Interest also exists due to the role of dry, bi-, and tri-reforming in the capture and utilization of CO2. New research efforts have explored efficient and effective reforming catalysts, as specifically applied to biogas. In this paper, we review recent developments in dry, bi-, and tri-reforming, where the CO2 in biogas is used as an oxidant/partial oxidant. The synthesis, characterization, lifetime, deactivation, and regeneration of candidate reforming catalysts are discussed in detail. The thermodynamic limitation and techno-economics of biogas conversion are also discussed.
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Energy Resources; Biocatalysis; Energy Storage
Review articles and database studies Mallon, William J; Jed Kuhn, John E
Journal of shoulder and elbow surgery,
20/May , Letnik:
32, Številka:
5
Journal Article
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•Low temperature (600 °C) CO2 conversion via reverse water gas shift chemical looping.•Stable operation for several conversion cycles – promising for industrial ...application.•Perovskite oxides with three transition metals in B-site demonstrate CO2 conversion.•Role of transition metals (Fe, Co, Mn) explored through multiscale approach.•Preferential surface segregation of Co and Fe found favorable for CO2 conversion.
Perovskite oxides of the form ABO3 have shown substantial promise in reverse water gas shift chemical looping (RWGS-CL) process for low temperature thermochemical CO2 conversion to CO. Transition metals on the ‘B’ site of these perovskite oxides hold the key to tuning the material properties essential for efficient CO2 conversion. The role of Co, Fe and Mn in LaBO3 has been investigated through a combined theoretical and experimental approach. Intrinsic oxygen vacancy formation characteristics of these materials and the electronic charge distribution were explored via ab-initio density functional theory (DFT) simulations, while the microscale properties like crystallite size and CO2 conversion yield were probed experimentally. Through this multiscale study, the material properties that govern the stable and enhanced CO2 conversion phenomenon by Fe rich perovskites as opposed to Co and Mn rich phases are differentiated.
Purpose To assess the effectiveness of a specific nonoperative physical therapy program in treating atraumatic full-thickness rotator cuff tears using a multicenter prospective cohort study design. ...Materials and methods Patients with atraumatic full-thickness rotator cuff tears who consented to enroll provided data via questionnaire on demographics, symptom characteristics, comorbidities, willingness to undergo surgery, and patient-related outcome assessments (Short Form 12 score, American Shoulder and Elbow Surgeons score, Western Ontario Rotator Cuff score, Single Assessment Numeric Evaluation score, and Shoulder Activity Scale). Physicians recorded physical examination and imaging data. Patients began a physical therapy program developed from a systematic review of the literature and returned for evaluation at 6 and 12 weeks. At those visits, patients could choose 1 of 3 courses: (1) cured (no formal follow-up scheduled), (2) improved (continue therapy with scheduled reassessment in 6 weeks), or (3) no better (surgery offered). Patients were contacted by telephone at 1 and 2 years to determine whether they had undergone surgery since their last visit. A Wilcoxon signed rank test with continuity correction was used to compare initial, 6-week, and 12-week outcome scores. Results The cohort consists of 452 patients. Patient-reported outcomes improved significantly at 6 and 12 weeks. Patients elected to undergo surgery less than 25% of the time. Patients who decided to have surgery generally did so between 6 and 12 weeks, and few had surgery between 3 and 24 months. Conclusion Nonoperative treatment using this physical therapy protocol is effective for treating atraumatic full-thickness rotator cuff tears in approximately 75% of patients followed up for 2 years.
Abstract In the 10 years since the current concept series entitled “The Disabled Throwing Shoulder: Spectrum of Pathology” was conceived and written, many studies have been reported that add much ...more information to the understanding of the disabled throwing shoulder (DTS). The editors of Arthroscopy and the authors of the original series believed that an update to the original series would be beneficial to provide an organized overview of current knowledge that could update the thought process regarding this problem, provide better assessment and treatment guidelines, and guide further research. A dedicated meeting, including current published researchers and experienced clinicians in this subject, was organized by the Shoulder Center of Kentucky. The meeting was organized around 5 areas of the DTS that were highlighted in the original series and appear to be key in creating the DTS spectrum and to understanding and treating the DTS: (1) the role of the kinetic chain; (2) the role and clinical evaluation of the scapula; (3) the role of deficits in glenohumeral rotation, glenohumeral internal rotation deficit, and total range-of-motion deficit in the causation of labral injury and DTS; (4) the role of superior labral (SLAP) injuries and rotator cuff injuries; and (5) the composition and progression of rehabilitation protocols for functional restoration of the DTS. The meeting consisted of presentations within each area, followed by discussions, and resulted in summaries regarding what is known in each area, what is not known but thought to be important, and strategies to implement and enlarge the knowledge base.
A technoeconomic analysis (TEA) and life cycle assessment (LCA) was conducted on the use of landfill gas (LFG) for electricity generation using an internal combustion engine. This study provides ...insights that can guide LFG waste to energy (WTE) operators on decisions concerning installation of contaminant removal from LFG for electricity generation. Four scenarios were analyzed; the first (Scenario 1) was a facility with a single siloxane removal unit (SREU) sized for 6 months of continuous use, the second (Scenario 2) was a facility with parallel SREUs sized for one month of use, the third (Scenario 3) was a facility with no SREU, and the fourth was a facility that flared all LFG captured. The TEA revealed that the chiller cost was over 50% the total purchase cost of the LFG pre-treatment system. When the complete LFG to electricity process was analyzed, the internal combustion engine had the highest percentage of total capital investment and the total annual cost. For the base case, it became economically beneficial to install a SREU at facilities with LFG flowrates greater than ∼2000 m3/h. Sensitivity analysis showed that at a base case of 1700 m3/h, LFG (50% CH4), and 50 mg/m3 D4, the net income of facilities in Scenarios 1 to 3 became positive at an electricity sales price greater than 5.5 cents/kWh. LCA revealed that Scenario 2 had the greatest CO2 emission reduction. Scenario 3 is observed to save less CO2 emissions as biogas flowrate increases due to frequent engine shutdowns. Although there are differences in the global warming potential (GWP 100) for Scenarios 1 to 3, with Scenario 2 being the best and Scenario 3 being the worst, the differences are very small. For this reason, economics alone are sufficient in decision making.
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•TEA and LCA conducted on LFG to electricity with and without pretreatment.•Siloxane removal unit economical in facilities with LFG flowrates over 2000 m3/h.•Siloxane removal units with continuous operation results in lowest CO2 emissions.•Source of avoided electricity on the global warming potential (GWP) was analyzed.
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