Experimental study of moment sharing in multi-joist timber-concrete composite floors from zero load up to failure

The critical T-sections of multi-joist timber-concrete composite (TCC) floors must be designed at ultimate for support shear force and midspan moment, both of which are influenced by transverse sharing, but to different extents. Prior experimental work has investigated only support reaction sharing and only up to serviceability loads. The present experimental study builds on that status quo by quantifying also moment sharing, via strain gauge layouts at quarter-span and midspan, along with reaction sharing via load cells at the supports of a multi-joist TCC specimen, over the entire load range up to failure. Use of steel mesh connectors bonded into hardwood laminated veneer lumber joists, and near geometric resemblance to a real building TCC floor recently built in London, were novel features of the specimen. The results show that midspan moment and reaction sharing both vary nonlinearly with load, but in distinctly different ways from each other (with up to almost 20% difference observed between them), in the progression between the uncracked, cracked and connection ductility regimes. In this approach reliable assessment of moment sharing depends on the quality of the recorded strains. Accordingly, the strain data were shown to be of high quality by converting these data to internal stress resultants that were then found to satisfy longitudinal equilibrium. It is concluded that this strain gauge layout is useful for future work aimed at building a database of transverse sharing of moments in TCCs

Bacteria as drug delivery vehicles

Doctor of PhilosophyDepartment of Chemical EngineeringStefan H. BossmannBoth chemotherapy for cancer treatment and antibiotic therapy for bacterial infections require systemic applications of the drug and a systemic application is always linked to a number of disadvantages. To circumvent these a targeted drug delivery system was developed. It utilizes the ability of phagocytes from the hosts own immune system to recognize and internalize antigens. Deactivated M. luteus, a non-pathogenic gram positive bacteria was loaded with high concentrations (exceeding the IC50 at least 60 fold in local intracellular concentration) the chemotherapeutics doxorubicin or DP44mt or with the bactericidal chlorhexidine. The modified bacteria is fed to phagocytes (Monocytes/Macrophages or neutrophils) and serves as protective shell for the transporting and targeting phagocyte. The phagocyte is recruited to the tumor site or site of infection and releases the drug along with the processed M. luteus via the exosome pathway upon arrival. The chlorhexidine drug delivery system was successfully tested both in vitro and in vivo, reducing the pathogen count and preventing systemic spread of a F. necrophorum infection in a mouse model. The doxorubicin drug delivery system reduced the viability of 4T1 cancer cells to 20% over the course of four days in vitro

Targeting the host response in sepsis: current approaches and future evidence

Sepsis, a dysregulated host response to infection characterized by organ failure, is one of the leading causes of death worldwide. Disbalances of the immune response play an important role in its pathophysiology. Patients may develop simultaneously or concomitantly states of systemic or local hyperinflammation and immunosuppression. Although a variety of effective immunomodulatory treatments are generally available, attempts to inhibit or stimulate the immune system in sepsis have failed so far to improve patients’ outcome. The underlying reason is likely multifaceted including failure to identify responders to a specific immune intervention and the complex pathophysiology of organ dysfunction that is not exclusively caused by immunopathology but also includes dysfunction of the coagulation system, parenchymal organs, and the endothelium. Increasing evidence suggests that stratification of the heterogeneous population of septic patients with consideration of their host response might led to treatments that are more effective. The purpose of this review is to provide an overview of current studies aimed at optimizing the many facets of host response and to discuss future perspectives for precision medicine approaches in sepsis

Optimized Pulse Patterns for Synchronous Machines with Non-Sinusoidal Back-EMF

Permanent magnet synchronous machines (PMSMs) used in automotive applications typically have a small number of stator slots. This distorts the air-gap flux distribution, thus resulting in a non-sinusoidal back-electromotive force (back-EMF), which in turn deteriorates the drive performance and decreases its efficiency. To address this, this paper proposes optimized pulse patterns (OPPs) that account for the back-EMF harmonics. In doing so, the computed OPPs can significantly improve the drive performance in terms of current and torque distortions. The presented numerical results verify the effectiveness of the proposed modulation method.Peer reviewe

Optimized Pulse Patterns for Anisotropic Synchronous Machines with Improved Current and Torque Properties

Accounting for the anisotropy of interior permanent magnet synchronous motors (IPMSMs) during the computation of optimized pulse patterns (OPPs) improves the current quality but at the cost of increased low-order torque harmonics. To address this issue, this paper reformulates the OPP problem such that both the current and torque harmonics are kept as low as possible. To do so, the current harmonics that result in pronounced torque harmonics are constrained in the optimization process. As demonstrated with the presented numerical results, the proposed OPPs manage to simultaneously produce current and torque of high quality over a wide range of operating points.Peer reviewe

Optimized Pulse Patterns for Anisotropic Synchronous Machines

Advanced optimized pulse patterns (OPPs) that account for the magnetic anisotropy of permanent magnet synchronous motors (PMSMs) have recently gained the attention of the automotive industry due to the improvements they offer in the current quality. However, these improvements can lead to torque quality degradation and an increased dc-link current ripple. To address this problem, a hybrid modulation scheme that combines isotropic and anisotropic OPPs is proposed in this paper to achieve the best overall performance over the whole range of operating points. To do so, as shown with the presented results, different OPPs are assessed and those with the best overall performance are selected.Peer reviewe

A hybrid soft solar cell based on the mycobacterial porin MspA linked to a sensitizer-viologen diad

A prototype of a nano solar cell containing the mycobacterial channel protein MspA has been successfully designed. MspA, an octameric transmembrane channel protein from Mycobacterium smegmatis, is one of the most stable proteins known to date. Eight Ruthenium(II) aminophenanthroline-viologen maleimide Diads (Ru-Diads) have been successfully bound to the MspA mutant MspAA96C via cysteine-maleimide bonds. MspA is known to form double layers in which it acts as nanoscopic surfactant. The nanostructured layer that is formed by (Ru-Diad)(8)MspA at the TiO2 electrode is photochemically active. The resulting "protein nano solar cell" features an incident photon conversion efficiency of 1% at 400 nm. This can be regarded as a proof-of-principle that stable proteins can be successfully integrated into the design of solar cells

Variable Switching Point Predictive Current Control for Multi-Phase Permanent Magnet Synchronous Drives

Finite control set model predictive control (FCS-MPC) is a promising method for the control of multi-phase machines, due to its capability to directly account for nonlinearities and multiple controlled variables. To overcome the drawback of high current ripples and excitation of harmonic currents in the so-called xy-subsystem, several methods have been proposed in the literature so far. This paper proposes an MPC-based method that achieves high granularity of switching by not only switching at the discrete time steps, but also within the sampling interval. In doing so, the discussed algorithm, referred to as variable switching point current control (VSP2CC), produces low current distortions, while still keeping the advantages of conventional FCS-MPC, such as fast dynamic behavior during transients. To highlight the above, VSP2CC is applied to a six-phase permanent magnet synchronous machine (PMSM) and compared with conventional FCS-MPC and MPC that employs virtual voltage vectors (VV-MPC).acceptedVersionPeer reviewe

An Experimental Assessment of Modulation Methods for Drive Trains Used In Electric Vehicles

As the number of electric automotive vehicles is rapidly growing, the need for higher efficiency and system-friendly operation of the drive train becomes more relevant and urgent. In this paper, the synchronous modulation schemes of selective harmonic elimination (SHE) and optimized pulse patterns (OPPs) are described and their performance benefits for drives used in automotive industry are highlighted. The presented experimental results based on an industrial drive demonstrate that OPPs achieve superior performance in terms of current distortions, system efficiency, and dc-link current ripple compared with conventional asynchronous space vector modulation (SVM).acceptedVersionPeer reviewe