A unified approach to one-dimensional elastic waves by the method of characteristics

Unified approach to one-dimensional elastic waves by method of characteristic

MCDIT 21 - A computer code for one-dimensional elastic wave problems

Computer program for one dimensional elastic wave problems connected with structural member

Geochemistry of reduced inorganic sulfur, reactive iron, and organic carbon in fluvial and marine surface sediment in the Laizhou Bay region, China

Understanding the geochemical cycling of sulfur in sediments is important because it can have implications for both modern environments (e.g., deterioration of water quality) and interpretation of the ancient past (e.g., sediment C/S ratios can be used as indicators of palaeodepositional environment). This study investigates the geochemical characteristics of sulfur, iron, and organic carbon in fluvial and coastal surface sediments of the Laizhou Bay region, China. A total of 63 sediment samples were taken across the whole Laizhou Bay marine region and the 14 major tidal rivers draining into it. Acid volatile sulfur, chromium (II)-reducible sulfur and elemental sulfur, total organic carbon, and total nitrogen were present in higher concentrations in the fluvial sediment than in the marine sediment of Laizhou Bay. The composition of reduced inorganic sulfur in surface sediments was dominated by acid volatile sulfur and chromium (II)-reducible sulfur. In fluvial sediments, sulfate reduction and formation of reduced inorganic sulfur were controlled by TOC and reactive iron synchronously. High C/S ratios in the marine sediments indicate that the diagenetic processes in Laizhou Bay have been affected by rapid deposition of sediment from the Yellow River in recent decades

Wave propagation in stepped and joined shells Annual report, 1 Sep. 1968 - 1 Sep. 1969

Shell impact response and wave propagation in cylindrical and conical shells by experimental and analytical method

An assessment of transient hydraulics phenomena and its characterization

A systematic search of the open literature was performed with the purpose of identifying the causes, effects, and characterization (modelling and solution techniques) of transient hydraulics phenomena. The governing partial differential equations are presented which were found to be used most often in the literature. Detail survey sheets are shown which contain the type of hydraulics problem, the cause, the modelling, the solution technique utilized, and experimental verification used for each paper. References and source documents are listed and a discussion of the purpose and accomplishments of the study is presented

Evidence for suboxic nitrification in recent marine sediments

The classical scheme of biogeochemical zones (BGZ) is known to be an oversimplification of the microbial processes that occur in organic-rich marine sediments. Results from a coupled deployment of pore-water gel probes in Loch Duich, Scotland, provide direct evidence for rapid recycling within the iron reduction (FeR) and sulphate reduction (SR) zones. High resolution porewater profiles obtained using diffusive equilibrium in thin films (DET) gel probes found a nitrate peak at the boundary between the FeR and SR zones. This non-steady state feature is consistent with recycling of reduced N occurring throughout the FeR zone. Both conventional pore-water iron profiles and results from diffusive gradient in thin films (DGT) probes indicate that iron is solubilised and precipitated in rapid Fe/S recycling reactions throughout the SR zone. The presence of such complex recycling reactions confirms the oversimplification of the classical BGZ scheme

Perspectives on new electrode technology for stimulating peripheral nerves with implantable motor prostheses

Journal ArticleAbstract-The limits of present electrode technology are being reached in current motor prostheses for restoring functional movement in paralyzed people. Improved devices require electrodes and stimulation methods that will activate muscles selectively and independently with less implanted hardware. A practical functional neuromuscular stimulation (FNS) system may need to employ extraneural, intraneural, epimysial, or intramuscular electrodes or a combination of these types. The limitations of current muscle electrodes and the anatomy of peripheral nerve innervation of muscle have pointed to stimulation of peripheral nerve trunks as a promising area for investigation. Attempts to use conventional (extraneural) peripheral nerve electrodes for selective activation of muscles in chronic applications have met with only limited success. Intraneural (intrafascicular) electrodes offer the advantages of greater selectivity and lower power requirements, but these may be offset by the difficulty of inserting delicate electrodes through the collagenous epineurium and perineurium while avoiding unacceptable amounts of trauma. Cuff electrodes require more power than intrafascicular ones but may provide more stable recruitment patterns over time, and the opportunity for retrieval and replacement

Anatomical Design and Production of a Novel 3-Dimensional Co-Culture System Replicating the Human Flexor Digitorum Profundus Enthesis

The enthesis, the specialized junction between tendon and bone, is a common site of injury. Although notoriously difficult to repair, advances in interfacial tissue engineering techniques are being developed for restorative function. Most notably are 3D in vitro co-culture models, built to recreate the complex heterogeneity of the native enthesis. While cell and matrix properties are often considered, there has been little attention given to native enthesis anatomical morphometrics and replicating these to enhance clinical relevance. This study focuses on the flexor digitorum profundus (FDP) tendon enthesis and, by combining anatomical morphometrics with computer-aided design, demonstrates the design and construction of an accurate and scalable model of the FDP enthesis. Bespoke 3D-printed mould inserts were fabricated based on the size, shape and insertion angle of the FDP enthesis. Then, silicone culture moulds were created, enabling the production of bespoke anatomical culture zones for an in vitro FDP enthesis model. The validity of the model has been confirmed using brushite cement scaffolds seeded with osteoblasts (bone) and fibrin hydrogel scaffolds seeded with fibroblasts (tendon) in individual studies with cells from either human or rat origin. This novel approach allows a bespoke anatomical design for enthesis repair and should be applied to future studies in this area.<br/

Sustainability Disclosure in the Leather Industry: A Content Analysis of Selected Sustainability Reports

Content: In today’s business environment, organisations are increasingly reporting their sustainability credentials through different channels. However, in a traditional industry with a complex supply chain as leather, many companies do not publicly disclose details of their sustainability activities, while a considerable number of companies report on the environmental sustainability aspect alone. Hence, this study identifies good practices of sustainability reporting, discussing the sustainability information extracted from the reports of a selected number of companies in the leather industry. A thematic content analysis was used to extract sustainability information from either the website, annual report, sustainability report or corporate social responsibility report of six leather companies. A review of existing literature assisted in categorising different practices under the three sustainability dimensions while a highlight of patterns among practices followed. The results show that the companies are observing a good practice of either dedicating a section of their website to revealing their sustainability activities or utilising their sustainability reports. Additionally, these companies follow a good practice of reporting their activities based on the economic, social and environmental sustainability dimensions, rather than focusing on just one of the aspects. Amongst the six companies, energy efficiency and reduction in greenhouse gases emission were the most occurring environmental sustainability practices. On the other hand, health and safety occurred as the dominant social sustainability practice of the leather industry, while economic sustainability practices have not been well defined, providing an opportunity for future research. Conclusively, the study provides a useful resource for managers and companies in the leather industry to learn from brands that have been embarking on sustainability efforts and assist them in getting a grasp of the concept, in readiness for strategy formulation, implementation and reporting. This study provides knowledge of the sustainability criteria to be met by small, medium sized and large leather supply chain actors on their sustainability journey. Take-Away: 1. The companies are observing a good practice of either dedicating a section of their website to revealing their sustainability activities or utilising their sustainability reports. 2. The companies also follow a good practice of reporting their activities based on the economic, social and environmental sustainability dimensions, rather than focusing on just one of the aspects. 3. Energy efficiency and reduction in greenhouse gases emission were the most popular environmental sustainability practices, health and safety was the dominant social sustainability practice while economic sustainability practices have not been well defined

Predicting the Efficacy of Future Training Programs Using Past Experiences

We investigate the problem of predicting the average effect of a new training program using experiences with previous implementations. There are two principal complications in doing so. First, the population in which the new program will be implemented may differ from the population in which the old program was implemented. Second, the two programs may differ in the mix of their components. With sufficient detail on characteristics of the two populations and sufficient overlap in their distributions, one may be able to adjust for differences due to the first complication. Dealing with the second difficulty requires data on the exact treatments the individuals received. However even in the presence of differences in the mix of components across training programs comparisons of controls in both populations who were excluded from participating in any of the programs should not be affected. To investigate the empirical importance of these issues, we compare four job training pro-grams implemented in the mid-eighties in different parts of the U.S. We find that adjusting for pre-training earnings and individual characteristics removes most of the differences between control units, but that even after such adjustments, post-training earnings for trainees are not comparable. We surmise that differences in treatment components across training programs are the likely cause, and that more details on the specific services provided by these programs are necessary to predict the effect of future programs. We also conclude that effect heterogeneity, it is essential, even in experimental evaluations of training programs record pre-training earnings and individual characteristics in order to render the extrapolation of the results to different locations more credible.