To assess acute performance-related effects of foam rolling, this study investigated the immediate effects of a standard foam rolling protocol on explosive strength of the plantarflexors and alpha motor neuron excitability in the soleus. Explosive strength was measured via vertical jump height (JUMP) and the Reactive Strength Index (RSI) obtained from a single leg drop jump. Alpha motor neuron excitability was measured by H reflex amplitude as H wave to M wave ratio (HM) obtained from the soleus muscle. JUMP and RSI measures were analyzed from nineteen subjects (12 male, 7 female) HM data were analyzed from 15 subjects (9 male, 6 female). Subjects attended one day of practice and instruction for the single leg drop jump and one day for data collection. One leg was randomly assigned to be the test leg (FL) and the other as the control (NL). The reported dominant leg and gender were also recorded for each subject. Subjects performed two single leg drop jumps per leg from a box height of 30 cm and then 10 soleus H reflexes were obtained. The intervention, which followed standard professional guidelines, consisted of 2.5 minutes of foam rolling for the FL and rest for the NL, followed by a 5 minute warm up on a cycle ergometer. The best jump and the average HM ratio were chosen for analysis. For each variable a post/pre ratio was calculated for statistical analysis. A 2x2x2 factor ANOVA with repeated measures on both factors was used for each variable. Analysis revealed no statistically significant differences for any of the variables, either as main effects or any of the interaction effects. Subjects trended towards a slightly larger post-intervention decrease in JUMP and RSI for the FL than the NL but this was not significant. It was concluded that a 2.5 minute intervention of foam rolling had no acute effect on explosive strength of the plantarflexors or alpha motor neuron excitability of the soleus. / text

I arbetet görs en ansats att utveckla verktyg för dimensionering av skyddsåtgärder vid röjning av RSV-ammunition. Till skillnad mot övriga verkansformer så saknar ammunitionsröjaren idag beräkningsmodeller eller annat adekvat stöd för fastställande av maximalt riskområde respektive för dimensionering av skadebegränsande åtgärder vid röjning av ammunition innehållande riktad sprängverkan. Arbetets fokus utgår från den militära nyttan med ett sådant verktyg, då en anpassning till röjningsverksamhetens informationstillgång, tidsförhållanden, arbetsmetodik och tekniknivå är direkt avgörande för om ett verktyg kan anses ändamålsenligt eller ej. Resultatet utgörs av förslag på två kompletta verksamhetsanpassade verktyg. Det första i form av en beräkningsmodell för dimensionering av skadebegränsande åtgärder, vilken kombinerar RSV-strålens penetrationsförmåga med detonationsavståndets inverkan. Det andra verktyget är en enkel modell för bedömning av det maximala riskområde som en RSV-stråle kan ge upphov till, vilken baseras på det dimensionerande strålsegmentets ballistiska bana. / This thesis is an attempt to develop models for design of protective measures during clearance of shaped charge ammunition. Unlike for other hazards, the EOD personnel are lacking adequate means for the establishment of the maximum hazardous area and for the design of measures for hazard confinement against the shaped charge effect. The development of the models is based on the military utility, by consideration of the limited information availability, the short time frames, the working methods and the technology level that are characteristic for EOD operations. The result is a suggestion of two complete and adapted tools for the design of protective measures. The first tool is a model for the design of measures for hazard confinement, which combines the jet penetration depth with the influence of the stand-off distance. The second tool is a simple model for estimation of the maximum hazardous area generated by the shaped charge jet, which is based on the trajectory of the most critical jet segment.

The aim of this diploma thesis is to focus on the resistance of concrete exposed to high temperatures especially with focus of resistance against explosive spalling as well as clarifying the mode of action of various types of polypropylene fibres. The theoretical part is an introduction to the issues of explosive spalling, its mechanisms and majority influencing factors. Further description of the processes taking place in the structure of concrete under extreme thermal load, distribution and size of pores in concrete, thermal load, temperature-time curves and their applications, methods of elimination of negative behaviour of concrete exposed to thermal loading (passive and active methods), mode of action of polypropylene fibres and more is also included in the theoretical part. The main aim of experimental part is to verify the function of polypropylene fibers of various Melt Flow Indexes (MFI) and dosage. Primarily, the test samples with content of the PP-fibers are compared to the reference sample without fibers. Secondarily, the samples with standard PP-fibers (with MFI 25) with dosage 2.0 kg/m3 are compared to samples with modified PP-fiber (with MFI 2500) of dosage 0.9 kg/m3. Photogrammetric images were used for evaluation and comparison of spalled surfaces and its depth. Determination of the softening temperature and melting point of the modified and standard PP-fibers was made by using a high temperature microscope video. The second part of the experimental work was to define concrete permeability at different temperatures and pressures. Permeability was measured at temperatures of 20°C, 90°C, 150°C, 175°C, 200°C, 225°C and 250°C and at pressure of 0.2, 0.4 and 0.6 MPa.

The purpose of this research was to explore how management explains the difference between the overall service quality ratings of staff at Company X versus the overall service quality ratings of Company X. The organisation conducts customer service measurements on a regular basis to monitor their customers overall service experience regarding the staff and the organisation. The results of the research identified a discrepancy regarding customer perceptions of the service they receive from the staff versus the service Company X is providing. Management was the focus of the study due to management having a direct or indirect influence on service gaps in the organisation. The SERVQUAL model, together with systems theory, was applied as a framework to explore management perceptions as to why a service quality gap exists. In-depth face-to-face interviews were conducted with management staff of Company X who are responsible for customer service. Thematic analysis was used to analyse the interviews and through content analysis six main themes were identified with various subthemes. The theoretical and empirical objectives were addressed and it was concluded that inconsistent practices within the organisation specifically the lack of consistent performance management can create an inconsistent service experience. The findings also revealed that Company X have various focus areas to improve the overall customer experience of the organisation. / Psychology / M.A. (Psychology (Research consultation))

La cristallisation en continu de nanoparticules énergétiques est un défi de longue date. Le Spray Flash Evaporation (SFE) est une technique majeure développée et brevetée en interne, pour la production en continu de matériaux énergétiques submicroniques ou nanométriques ; la technologie se base sur la surchauffe d’un solvant pulvérisé dans le vide et s’évaporant de manière flash. Ce présent travail de recherche a pour but de comprendre et contrôler la cristallisation au sein du procédé SFE. Le RDX et le cocristal CL-20:HMX 2:1 sont étudiés. La sursaturation, concernant le SFE, est une fonction du temps et de l’espace liée aux tailles et vitesses de gouttes : elle fut variée par un anti-solvant et par l’amélioration du SFE avec un système double buse. Ensuite, PVP 40K et PEG 400 ont été utilisés afin de contrôler la nucléation et la croissance. Les particules ont pu être ajustées d’une taille de 160 nm à 5 µm, avec des morphologies facettées ou sphériques et avec des sensibilités moindres. / The continuous formation of nanosized energetic material is a long-standing challenge. Spray Flash Evaporation (SFE) is a major technique, internally developed and patented, for continuously producing energetic materials at submicron or nano scale; it relies on the superheating of a solvent sprayed into vacuum and thus flashing. This present research project aims to understand and control the crystallisation occurring in the SFE process. RDX and the cocrystal CL-20:HMX 2:1 was studied overcome the limited in situ characterizations also. The supersaturation is a function of time and space in SFE, linked to the size distribution and velocity of droplets. Supersaturation was raised with an anti-solvent and by the enhancement of the SFE with a dual nozzle system. Then PVP 40K and PEG 400 were successfully used to alter the nucleation and the growth. The particles were subsequently tuned from 160 nm spheres to 5 µm grains and were less sensitive, especially toward electrostatic discharge.

This thesis deals with the behavior of cement concrete at high temperature with a focus on the impact behavior of aggregate, cement type and polypropylene fiber reinforcement. The theoretical part describes the issue of cement concrete at high temperatures, especially processes in the cement matrix, aggregates and polypropylene fibers. Furthermore, theoretical part describes the selection of a suitable type of cement and aggregates in concrete exposed to high temperatures. In the experimental part was designed the concrete composition with various kinds different types of aggregates and two types of cements. The temperature stress of test samples was performed according to ISO standard temperature curve 834. Subsequently, was made the verification of the physic-mechanical properties such as changes in bulk density and compressive strength after heat load. Moreover, the surface appearance of samples after heat load was evaluated, especially the occurrence of samples, the crack width and explosive spalling. Mineralogical composition changes of prepared samples before and after heat load were observed via X-ray diffraction analysis. Finally, we made a photogrammetry on a test plates after heat load which defined the size of the area and depth of spalling concrete surface.

The growing need for fast sampling of explosives in high throughput areas has increased the demand for improved technology for the trace detection of illicit compounds. Detection of the volatiles associated with the presence of the illicit compounds offer a different approach for sensitive trace detection of these compounds without increasing the false positive alarm rate. This study evaluated the performance of non-contact sampling and detection systems using statistical analysis through the construction of Receiver Operating Characteristic (ROC) curves in real-world scenarios for the detection of volatiles in the headspace of smokeless powder, used as the model system for generalizing explosives detection. A novel sorbent coated disk coined planar solid phase microextraction (PSPME) was previously used for rapid, non-contact sampling of the headspace containers. The limits of detection for the PSPME coupled to IMS detection was determined to be 0.5-24 ng for vapor sampling of volatile chemical compounds associated with illicit compounds and demonstrated an extraction efficiency of three times greater than other commercially available substrates, retaining >50% of the analyte after 30 minutes sampling of an analyte spike in comparison to a non-detect for the unmodified filters. Both static and dynamic PSPME sampling was used coupled with two ion mobility spectrometer (IMS) detection systems in which 10-500 mg quantities of smokeless powders were detected within 5-10 minutes of static sampling and 1 minute of dynamic sampling time in 1-45 L closed systems, resulting in faster sampling and analysis times in comparison to conventional solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis. Similar real-world scenarios were sampled in low and high clutter environments with zero false positive rates. Excellent PSPME-IMS detection of the volatile analytes were visualized from the ROC curves, resulting with areas under the curves (AUC) of 0.85-1.0 and 0.81-1.0 for portable and bench-top IMS systems, respectively. Construction of ROC curves were also developed for SPME-GC-MS resulting with AUC of 0.95-1.0, comparable with PSPME-IMS detection. The PSPME-IMS technique provides less false positive results for non-contact vapor sampling, cutting the cost and providing an effective sampling and detection needed in high-throughput scenarios, resulting in similar performance in comparison to well-established techniques with the added advantage of fast detection in the field.

Fast detection and identification of unknown substances is an area of interest for many parties. Raman spectroscopy is a laser-based method allowing for long range no contact investigation of substances. A Coded Aperture Snapshot Spectral Imaging (CASSI) system allows for fast and efficient measurements of hyperspectral images of a scene, containing a mixture of the spatial and spectral data. To analyze the scene and the unknown substances within it, it is required that the spectra in each spatial position are known. Utilizing the theory of compressed sensing allows for reconstruction of hyperspectral images of a scene given their CASSI measurements by assuming a sparsity prior. These reconstructions can then be utilized by a human operator to deduce and classify the unknown substances and their spatial locations in the scene. Such classifications are then applicable as decision support in various areas, for example in the judicial system. Reconstruction of hyperspectral images given CASSI-measurements is an ill-posed inverse problem typically solved by utilizing regularization techniques such as total variation (TV). These TV-based reconstruction methods are time consuming relative to the time needed to acquire the CASSI measurements, which is in the order of seconds. This leads to a reduced number of areas where the technology is applicable. In this thesis, a Generative Adversarial Network (GAN) based reconstruction method is proposed. A GAN is trained using simulated training data consisting of hyperspectral images and their respective CASSI measurements. The GAN provides a learned prior, and is used in an iterative optimization algorithm seeking to find an optimal set of latent variables such that the reconstruction error is minimized. The results of the developed GAN based reconstruction method are compared with a traditional TV method and a different machine learning based reconstruction method.  The results show that the reconstruction method developed in this thesis performs better than the compared methods in terms of reconstruction quality in short time spans.

Hold down release mechanisms (HDRMs) are used for tightly attaching segments of bodies together when it is desired to release them rapidly at some point. When transporting sensitive payloads on launch vehicles, the challenge arises of releasing the fastened segments of the spacecraft without risking damage to the costly equipment. Non-explosive HDRMs are favourable from a safety perspective as there is a lower risk of producing potentially destructive shock-waves throughout the structure.  One variant of a non-explosive HDRM uses a so called 'split spool initiator'. This initiator can only be used once in the actuator mechanism and to reuse the HDRM the initiator must be replaced. The purpose of this thesis is to design an improved split spool initiator which can be reusable while conserving the functionality aspects of the existing design. To achieve this, different ideas were considered and ultimately a solution using shape memory alloys (SMAs) was explored. A prototype was constructed to demonstrate the functionality of the design and simulations are done to determine the forces acting on different parts of the mechanism. / Hold down release-mekanismer (HDRM) används för att säkert kunna fästa samman delar av strukturer för att sedan kunna lossa dessa vid rätt tillfälle. När det transporteras känslig last på exempelvis rymdfarkoster uppkommer utmaningen att göra så på ett sätt som inte riskerar att skada den ofta dyra utrustningen. Det finns en mängd olika HDRM, dessa kan delas upp i två typer som är icke explosiva release-mekanismer och pyrotekniska release-mekanismer. Icke explosiva release-mekanismer har en fördel över pyrotekniska som är att de inte producerar potentiellt destruktiva chock-vågor som sprids genom strukturen. En typ av icke-explosiva release-mekanismer är den så kallade split spool-initieraren. Denna kan endast användas en gång när fästelementet är aktiverat och för att kunna använda fästelementet igen måste hela initieraren bytas ut. Syftet med denna studie har varit att att designa en förbättrad split spool-initierare som är återanvändbar, medan funktionaliteten hos den ursprungliga designen är bevarad. För att åstadkomma detta övervägdes olika idéer och slutligen valdes en lösning som använder minnesmetaller eller Shape memory alloys på engelska (SMA). En prototyp konstruerades för att demonstrera funktionaliteten hos designen. Simuleringar gjordes även för att bestämma krafter som agerade på split spool-strukturen och för att få en överblick över spänningsfördelningen genom initieraren.

This theses is speaking about the posibilities of commit a terrorist action through the agency of the dangerous chemical substances or explosive devices in the Czech Republics shopping centers. Teoretical part wants to give an informations about legislative base of this dilema, characteristic of the shopping centers, characteristic of the disposable resources to the perpetration the terrorist action and the instruments for the solution of theses expectional events. The unique survey is base of practical parts. The survey was carry out to the fading out the best possibilities to commit a terrorist action. More than twenty experts were the respondents. The another parts of the practical part are the descriptions of the scenarios of the terrorist action, suggestions to the protection of the persons in the shopping center and the crisis plan for the shopping center to the solution of the expectional event which is describe in this theses.