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1
Anderson, Rosanna Leah. "Experimental characterization of ice hockey sticks and pucks." Online access for everyone, 2008. http://www.dissertations.wsu.edu/Thesis/Spring2008/R_Anderson_042308.pdf.
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Westoby, Crysta Ann-Marie. "Toe picks and hockey sticks : children and the gendering of figure skating and hockey." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44359.
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Figure skating and hockey are two sports that currently are gendered as feminine and masculine, respectively. This study originated in my concern that gendered sports may be a discouragement to youth participation. This research project was undertaken in order to understand how figure skating and hockey are gendered in a community arena in rural British Columbia and how this might impact youth involvement. My methods included participant observation, interviews, and focus groups. The data from these ethnographic techniques are interpreted according to the concept that people both actively reinforce and resist the gendering of their sport. As a result of the study, I found that gendering hockey as masculine was often contested by female hockey players. Although females in recreational hockey seem to be largely accepted and welcome on mixed teams, the opposite was the case for females pursuing hockey competitively alongside their male peers. Gendering figure skating as feminine was largely uncontested, in part due to the lack of males participating in the sport. In addition, the interactions between hockey players and figure skaters frequently served to reinforce the gendering of these two sports. The key recommendation from this study is for both groups to be aware that the gendering of their sports seems to be a subconscious deterrent and they should take steps to counteract this trend.
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Hirshon, Nicholas H. ""We Want Fish Sticks!": The Failed Rebranding of the New York Islanders." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1467907905.
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Dawson, Thomas. "Red Lines & Hockey Sticks : A discourse analysis of the IPCC’s visual cultureand climate science (mis)communication." Thesis, Uppsala universitet, Institutionen för ABM, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-445887.
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Within the climate science research community there exists an overwhelming consensus on the question of climate change. The scientific literature supports the broad conclusion that the Earth’s climate is changing, that this change is driven by human factors (anthropogenic), and that the environmental consequences could be severe. While a strong consensus exists in the climate science community, this is not reflected in the wider public or among policymakers, where sceptical attitudes towards anthropogenic climate change is much more prevalent. This discrepancy in the perception of the urgency of the problem of climate change is an alarming trend and likely a result of a failure of science communication, which is the topic of this thesis. This paper analyses the visual culture of climate change, with specific focus on the data visualisations comprised within the IPCC assessment reports. The visual aspects of the reports were chosen because of the prioritisation images often receive within scientific communication and for their quality as immutable mobiles that can transition between different media more easily than text. The IPCC is the central institutional authority in the climate science visual discourse, and its assessment reports, therefore, are the site of this discourse analysis. The analysis tracks the development and variations in the IPCC’s visual culture, investigates in detail the use of colour and the visual form of the “Hockey Stick” graph. This work is undertaken to better understand the state of the art of climate science data visualisation, in an effort to suggest the best way forward to bridge the knowledge gap between the scientific community and the public on this important issue. The thesis concludes that a greater emphasis on the information aesthetics of their data visualisations could benefit the IPCC’s pedagogical reach, but that it may also be argued that it is not the IPCC’s role in climate change discourse to produce the most visually persuasive images. That they exist as a tone-setting institution that provides authority to entities that are better geared towards wider communication, such as journalism and activism.
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Hove, Philip. "Haptic Perception of Affordances of a Sport Implement: Choosing Hockey Sticks for Power Versus Precision Actions on the Basis of “Feel”." Cincinnati, Ohio : University of Cincinnati, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1097535192.
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McHutchon, Mark A. "An engineering approach to hockey stick design." Thesis, University of Sheffield, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619254.
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Wu, Tong-Ching Tom. "The performance of the ice hockey slap and wrist shots : the effects of stick construction and player skill." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33949.
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This thesis was to examine the interaction of players' skill level, body strength, and various types of stick construction and stiffness on the performance of the hockey shots. Forty subjects were tested, and each subject performed the slap and wrist shots with different stick shaft constructions and stiffness. Shot mechanics were evaluated by simultaneously recording of ground reaction forces, stick movements and peak puck velocity. Data analyzed with a 4-way ANOVA for several dependent variables. The results indicated that: (1) the slap shot was faster than the wrist shot corresponding to greater vertical force, stick bending and hand placement; (2) the puck velocity was influenced by skill level and body strength not stick type; and, (3) the skilled players generated greater vertical force and stick bending by adjusting their hand positions. Further studies are needed to address the specific stick material and construction properties.
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Michaud-Paquette, Yannick. "Ice hockey stick and puck biomechanical predictors of wrist shot accuracy." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19237.
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The purpose of this study was to identify the movement patterns of the ice hockey stick from a wrist shot that corresponds to the accuracy of puck trajectory. A total of twenty five subjects participated in this study; each performed 10 successful wrist shots on four targets. Performances were evaluated by simultaneously recording the movements of the stick's shaft and blade and of the puck with infra-red based motion capture (Vicon®) system (240 Hz) Kinematics of the shaft and blade of the hockey stick were examined using a multiple regression analysis using the accuracy score as the dependant variable. The results indicate that accurate shooters tended to alter release parameters (puck release orientation and velocity), loading mechanics and blade orientation to achieve proper puck trajectory explaining 40% and 76% of the accuracy variances for the bottom and top corners respectively. Shooters were more accurate shooting at bottom corners than at the top corners (67% vs 45%). These analyses helped to identify key stick usage variables that predict accuracy during the execution of stationary wrist shots. Further studies are needed to identify the whole body kinematic patterns associated with the hockey stick kinematics.<br>L'objectif premier de cette étude était d'identifier les mouvements caractéristiques du bâton de hockey correspondant à la précision de tirs du poignet stationnaire à travers différents niveaux d'habiletés. Un total de vingt-cinq sujets ont fait parti de l'échantillon. Chacun d'eux ont dû réussir correctement dix lancers dans chacune des quatre différentes cibles. La performance des sujets a été évaluée en mesurant le déplacement du bâton et de la rondelle à l'aide de marqueur réfléchissants qui était filmé à l'aide d'un système d'analyse du mouvement composé de caméra infrarouge (Vicon®), le tout étant enregistré à 240 Hz. La cinématique du manche et de la palette du bâton de hockey ont été analysées par le biais d'une analyse de régression multiple en utilisant le niveau de précision comme étant la variable dépendante. Les résultats démontrent que les joueurs les plus précis ont tendance à modifier les paramètres de projection (orientation et vitesse de la rondelle), le mécanisme de mise en charge du bâton ainsi que l'orientation de la palette pour obtenir la trajectoire de rondelle désirée avec des modèles de prédiction pouvant expliqué respectivement 40% et 76% de la variabilité de la précision pour les cibles inférieures et supérieures. Les sujets étaient plus précis pour les cibles inférieures que pour les cibles supérieures (67% vs 45%). Cette analyse a permis d'identifier les variables clés pour effectuer un lancer du poignet stationnaire précis mais d'autres recherches doivent être effectuées pour identifier les mouvements du corps qui sont associés avec la cinématique du bâton de hockey.
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Villaseñor-Herrera, Alejandro. "Recoil effect of the ice hockey stick during a slap shot." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81450.
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This thesis examined the 'recoil' effect of the ice hockey stick shaft during a stationary slap shot. Nine subjects were tested. Four were classified as 'elite' and the remaining five as the 'recreational' group. Their performances were evaluated by simultaneously recording stick movement and bending from high-speed video capture (1000 Hz) and puck acceleration from a triaxial accelerometer positioned inside the puck. Data were analyzed with a one-way ANOVA for several dependant variables including final puck velocity, stick shaft bending, blade-puck contact time and stick kinetic energy. The results indicated that: (1) the puck velocity was influenced by skill level, blade-puck contact time and stick bending energy but not puck acceleration. Further studies are needed to address the influence of events before and after blade-puck contact as well as the strength of the player on the mechanical energy and impulse given to the puck.
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Zane, Lisa. "Force measures at the hand-stick interface during ice hockey slap and wrist shots." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110526.
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The purpose of this study was to quantify the contact forces between the lower and upper hands to the stick shaft during the ice hockey slap and wrist shot. Four cohorts (male/female x high/low calibre; HC, LC) of ice hockey players were tested using three sticks of different shaft bending stiffnesses (77, 87, 102). Forty-one subjects (21 male, 20 female) performed seven slap and seven wrist shots with each of the three stick types. Force at the stick-hand interface was recorded at 1000 Hz using 32 piezoresistive sensors about the shaft at the upper and lower-hand grip locations. The results demonstrated the feasibility for direct measurement of forces at the hand-stick interface while executing shooting tasks in ice hockey. As anticipated, peak forces acquired during both the slap and wrist shot differed by calibre and by gender, with males exhibiting higher forces than females, and HC players demonstrating higher forces than LC players, within each gender; however, stick type was not a significant factor. Notably, each player displayed unique, repeatable "force signatures". In general, for both slap and wrist shots, grip force patterns demonstrated typical bimanual coordination patterns pertinent to understanding the mechanical dynamic control of the stick for effective performance.<br>Le but de cette étude était d'examiner les forces de contact entre les mains et le baton de hockey pendant l'exécution de lancers frappés et de tirs du poignet. Quatre cohortes (homme/femme x haut / bas calibre; HC, LC) de joueurs de hockey sur glace ont été testés en utilisant trois bâtons de rigidités différentes (77, 87, 102). Quarante et un sujets (21 hommes, 20 femmes) ont effectué sept lancers frappés et sept tirs du poignet avec chacun des trois types de bâton. La force de pression a été enregistrée à 1000 Hz en utilisant 32 capteurs piézorésistifs aux interfaces entre la main et le bâton. Les résultats ont démontré la faisabilité de la mesure directe des forces à l'interface main-bâton lors de l'exécution de tirs au hockey sur glace. Les forces de pointe atteintes au cours de lancers frappés et de tirs du poignet différaient en fonction du calibre et du sexe, les hommes présentant des forces supérieures comparativement aux femmes. De plus, les joueurs de HC ont démontré des forces supérieures par rapport aux joueurs LC. Par contre, le type de bâton ne représentait pas un facteurs significatif pour la production de force qui plus est, chaque joueur a affiché une 'signature' de force reproductible et constante. En général, les modèles de forces pour les lancers frappés et les tirs des poignets ont démontré des pattrons de coordination bimanuelle à la compréhension du contrôle mécanique dynamique du bâton et possiblement a l'évaluation de la performance.
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Hannon, Ashley. "Dynamic strain profile of the ice hockey stick: Comparisons of calibre and shaft stiffness." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95241.
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The primary purpose of this study was to develop a method to quantify the dynamic strain profile (DSP) of an ice hockey stick's shaft, and secondly, to use this method to assess the potential influence of player skill calibre and stick shaft properties on DSP during both the slap and wrist shots. Seventeen adult males performed a series of shots using two different stiffness ranked sticks in a laboratory setting on synthetic ice surface. These subjects were subdivided as high and low calibre players. Dependent measures included were: 1) five paired strain gauge responses along the shaft's length recorded at 10 KHz, and 2) kinematics of the puck, stick and trail arm grasping the stick recorded at 300 Hz using a Vicon MX system. 2 x 2 MANOVAs were conducted for each of slap shot and wrist shot trials. The results demonstrated the feasibility of quantifying DSP such that an unambiguous rank order in maximum strain responses was obtained. Further, DSP were sensitive to both factors of player calibre and stick stiffness properties; that is, greater bend induced strains observed by high calibre player and lower stiffness sticks. Two kinematic differences relating to technique were observed: high calibre players showed less elbow flexion during the slap shot and greater wrist flexion during wrist shots. Lastly, with regards to time to maximum strain, high calibre players performed slap shots 3 to 4 times faster than the lower calibre players.<br>L'objectif principal de cette étude était de développer une méthode pour la quantification des différents profils de déformation dynamique de bâtons de hockey et de utiliser qu'est méthode pour examiner l'influence cinématiques du des joueurs de niveau élite et des joueurs de niveau récréatif pour les lancers frappes (SS) et des tirs du poignet (WS). Dix-sept sujets males ont donc effectué en laboratoire une série SS et de WS avec deux bâtons de hockey différent sur une surface de glace synthétique et étaient divisés en deux groupes, un pour le niveau élite et l'autre pour le niveau récréatif. Les mensures dépendantes étaient 1) la déformation du bâton a cinq étroits sur le manche du bâton à l'aide d'un système maison enregistrant à une fréquence de 10 KHz, et 2)la cinématique du bâton, de la rondelle et du membre supérieur le plus bas sur le bâton ont été enregistré à une fréquence de 300 Hz à l'aide d'un système Vicon MX . Deux MANOVA de forme 2x2 ont été effectuées, une pour les lancers frappés ainsi qu'une pour les lancers du poignet. Les résultats ont démontré la faisabilité de la quantification des différents profils de déformation dynamique de bâtons telle que l'ordre de classement sans ambigüité en réponse contrainte maximale a été obtenue. Des différences ont été trouvées pour la déformation aux différents capteurs à travers les niveaux d'habileté ainsi qu'à travers les bâtons. La déformation maximale était différente dépendamment du calibre et du bâton et ce pour les deux types de lancer. De plus, les joueurs de calibre récréatifs ont démontrés un délai significativement plus long entre la déformation maximal et le début du lancer pour les lancers frappés. Des différences cinématiques ont été trouvées au moins flexion du coude entre les calibres pour le niveau élite pour les lancers frappés et plus flexion pour le poignet pour les tirs du poignet pour le n
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Pike, Stephanie N. "BATTLING AMBIGUITY: A PUBLIC GUIDE TO UNDERSTANDING THE SCIENCE BEHIND THE GREAT ¿¿¿¿HOCKEY STICK¿¿¿¿ DEBATE." Kent State University Honors College / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1335245672.
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Basso, Renato Gioielli. "Estratégia de planejamento de produção e os sistemas ERP em ambientes sujeitos ao fenômeno hockey-stick." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3136/tde-19072016-120435/.
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O ambiente competitivo atual tem colocado pressão no processo de tomada de decisão no mundo corporativo. Os trade-offs das prioridades competitivas discutidos na elaboração da estratégia como custo, qualidade, serviço e flexibilidade já não são suficientes. Estes trade-offs, embora importantes no curto prazo, devem ser compatibilizados de modo que as empresas que tenham o melhor balanço entre eles devam ter resultado superior. Um dos trade-offs bastante discutido é o equilíbrio entre serviço e estoque. A percepção é que seja improvável alcançar excelência no serviço sem ter um considerável nível de estoque. Deste cenário nasce então o paradoxo do uso de sistemas MRP (Material Requirement Planning) versus sistemas JIT (Just in Time), ou melhor, sistemas empurrados versus puxados, já que a escolha por um ou outro sistema tem ligação íntima com a gestão de estoque. Se por um lado os sistemas MRP são largamente utilizados, via softwares ERP, por outro sistemas JIT têm trazido importantes melhorias nos resultados. Embora muitas empresas considerem a adoção exclusiva de um ou outro sistema, algumas delas têm adotado um processo híbrido com o objetivo de tirar o melhor de cada sistema e gerar assim desempenho superior. O objetivo deste trabalho é investigar como as empresas inseridas em mercados caracterizados pela concentração de demanda no final do mês (fenômeno conhecido como hockey-stick), e baixo acerto nas previsões de demanda, estão aplicando suas estratégias de planejamento de produção e seus ERP. Se por um lado a baixa acurácia nas previsões causa um problema na aplicação de estratégias empurradas de planejamento, pois requer um alto estoque de segurança associado, por outro a concentração de embarque dificulta a adoção de uma estratégia puramente puxada, já que o sistema não tem a estabilidade necessária. Para cumprir com este objetivo seis estudos de caso foram conduzidos e os resultados encontrados, suportados pela teoria, sugerem o aparecimento de um modelo híbrido eficaz para planejamento no ambiente estudado assim como o aparecimento de um sistema DSS (Decision Support System). Outra contribuição desta pesquisa foi identificar, em um dos casos, uma empresa que conseguiu atacar de maneira eficaz o fenômeno em sua causa raiz neutralizando assim seus efeitos.<br>The highly competitive environment of modern times has put pressure on the decision-making process in the corporate world. The trade-offs of competitive priorities such as cost, quality, service and flexibility are no longer enough. These trade-offs, albeit important in the short term, must be matched so that companies that have the best balance between them should have superior results. One of the tradeoffs widely discussed is the balance between service level and inventory. The perception is that excellence is not likely to be achieved in service without having a significant level of inventory. From this scenario comes the paradox of using MRP systems (Material Requirement Planning) versus JIT systems (Just in Time), or rather \"pushed\" systems versus \"pulled\" systems since the option for one or the other system has a close connection with inventory management. On the one hand, MRP systems are widely used in industry through ERP software; on the other hand, JIT systems have obtained better results. While many companies consider adopting one or another system, some of them adopt a hybrid process with the goal of taking the best of each system and generate superior performance. The purpose of this research is to investigate how companies inserted in markets characterized by sales peak at the end of the month (hockey-stick phenomenon), and low accuracy in demand forecasts, are applying their production planning strategies and their ERP. Low forecast accuracy causes a problem in applying pushed strategies as it requires a high safety stock associated. Conversely, the sales peak hinders the adoption of a purely pull strategy since the system does not have the necessary stability. To meet this goal, six case studies were conducted and the results found and supported by the theory suggest the emergence of an effective hybrid model for planning in the environment studied as well as the appearance of a DSS (Decision Support System). Another contribution of this research was to identify in one of the cases a company that managed to effectively tackle the phenomenon in the root cause, neutralizing its effects.
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Saucedo, Antonio Jr. "Pascal's Triangle, Pascal's Pyramid, and the Trinomial Triangle." CSUSB ScholarWorks, 2019. https://scholarworks.lib.csusb.edu/etd/855.
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Many properties have been found hidden in Pascal's triangle. In this paper, we will present several known properties in Pascal's triangle as well as the properties that lift to different extensions of the triangle, namely Pascal's pyramid and the trinomial triangle. We will tailor our interest towards Fermat numbers and the hockey stick property. We will also show the importance of the hockey stick properties by using them to prove a property in the trinomial triangle.
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Li-Nien, Hsu, and 許利年. "Modal Verification and Vibration Characteristics Analysis of Hockey Stick." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/54837593988566948132.
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碩士<br>國立屏東科技大學<br>機械工程系所<br>98<br>This text mainly focuses on the vibration characteristic of hockey stick through the method of the EMA (Experimental Model Analysis) and theoretical FEA (finite element analysis ). First, the theoretical model parameters,including natural frequency, model shape, will be observed by means of the FEA. Second, the theoretical model verification will be compared with the experimental model parameters. Finally, the certificated finite element model could be treated as
an analytical model; The Hockey in three types of boundary conditions, i.e.,free-free,free-fixed and free-spring,is also analyzed to compare their modal frequencies and
mode shapes. Find spring and freedom,fixing the relationship between the boundary.The modal properties of hockey in grips condition can then be predicted. The proposed analysis and experimental methodology can be beneficial to the design of hockey. The virtual testing can be enhanced in the future.
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吳鴻鈞. "Modal Verification and Vibration Characteristics Analysis of Field Hockey Stick." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/66307833292539369995.
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碩士<br>國立屏東科技大學<br>機械工程系所<br>98<br>The purpose of this study is investigate the reverse engineering technique for the reconstruction of the CAD model for field hockey stick. This study first adopts Finite Element Analysis (FEA) and Experimental Modal Analysis (EMA) to perform model verification for field hockey stick. Both FEA and EMA results were compared in order to validate finite element modal. The natural frequencies and mode shapes can be obtained by FEA. Experimental natural frequencies, damping ratios and mode shapes of the field hockey stick can also be obtained by EMA. From the verification between theoretical and practical structural modal testing results. The finite element modal can be treated as an analytical model. Finally, the field hockey stick in two types of boundary conditions, and perform theoretical analysis in order to compare their vibration characteristics and differences, find the relationship between the boundary conditions.
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"Estimación e inferencia de los parámetros de la distribución Hockey Stick." Tesis, Universidad de las Américas Puebla, 2004. http://catarina.udlap.mx/u_dl_a/tales/documentos/meii/madrigal_l_e/.
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Chen, Hung-Sheng, and 陳宏昇. "Study of Hockey Stick Mesogens – Relationship of Structure, Mesophase and Property." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/19374073632322644720.
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碩士<br>淡江大學<br>化學學系碩士班<br>96<br>The purpose of this research is to probe into “hockey stick ”shaped mesogens. The mesophase
were studied by optical polarizing microscopy. Differertial scanning calorimetry and powder x-ray
diffraction.
The mesogens were obtained by esterification of 3-alkoxy-4-methoxybenzoic acid,
3-alkoxycinnamic acid, 3-alkoxy-(4’-phenolyl)benzoate and 3-alkoxy-4’-hydroxylstilbene with
4-alkoxy-(4’-phenolyl)benzoate, 4-alkoxy-(4’-(4’’-phenolyl)benzoyloxy)benzoate and
4-alkoxy-4’-biphenyl-carboylic acid. The resultant mesogens mBIIABBn, Me-mBBBn, Me-mBBBBn,
mBIIABBBn, Me-mBB-B2n, mBB-B2n and mBIIB-B2n, exhibit nematic, SmA, SmC and SmCa
phases.
The texture of nematic exhibit schlieren textures with 2-brush or 2-and 4-brush defects. For a
homogeneously aligned (EHC cell) nematic phase of hockey stick mesogen, with the alignment direction
parallel to one of the crossed polarizers, a uniform dark texture with strong optical fluctuation was
observed. Upon application of a DC field, pairwise and uniformly spaced birefringent straight stripes
developed with the stripe long axis parallel to the rubbing direction. The pairwise birefringent stripes
turned color when the sample was rotated, and the colors were exchanged with a reversing rotation.
The textures of SmC phase exhibit schlieren and broken focal conic textures. The schlieren texture
displayed 2- and 4-brush defects. Defects of 2-brushes have been considered as evidence for the anticlinic
arrangement of the neighboring layers in the smectic phase of calamitic mesogens. There were elongated
domains of various sizes with long axes parallel to the rubbing direction and with disclinations between
them. Thedomains were of two different colors when the sample was rotated or the polarizers were
decrossed. The domain colors changed with application of DC fieids.
The textures of SmCa exhibit schlieren and broken focal conic textures. The schlieren texture
containing plenty of 2-brush defects. The optical appearance across this schlieren texture was more
uniform than that of SmC phase. There were floating liquids sweeping through the sample, a behavior
easily observed during temperature variation. Some periodic parallel stripes, rather similar to the pitch
band observed for chiral smectic phases, occurred in the broken focal conic areas. The color chwnges and
variation of textures under electric fields resembled that of SmC phase.
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Yao, Shi-Yi, and 姚世逸. "Synthesis and properties of hockey stick liquid crystals with oligo(ethyleneoxy) side chain." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/27373138495787244712.
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碩士<br>淡江大學<br>化學學系碩士班<br>98<br>Ten series of hockey stick molecules were synthesized with different ethyleneoxy side chains and aromatic cores. Mesophase properties of these hockey stick mesogens were studied by polarizing optical microscopy, differential scanning calorimetry, powder X-ray diffraction, and electric field effect.
As compared with the meta-positioned hydrocarbon chain analogues, the ethyleneoxy derivatives exhibited slightly smaller mesophase ranges, mainly due to the narrowing of the smectic phase thermal ranges. For the ether and ester linked ethyleneoxy side chain derivatives, ester linked derivatives showed appreciable lowering of melting point but without anticlinic smectic phase.
The optical and electric-field effect of the synclinic and anticlinic smectic phases, SmC and SmCa, resemble those of known hockey stick mesogens, i.e., two types of domains with opposite tilting directions and color exchange with opposite rotation of sample. Color of the SmC changed with increasing electric field strength, the pitch-band-like lines of the SmCa domains diminished with field strength.
Smectic B phase existed, from X-ray diffraction and optical appearance, for two of the newly synthesized four-ring skeleton hockey stick mesogens.
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Chuang, Tsung-Han, and 莊宗翰. "Effect of Flurorinated Extent on the Mesophases of Hockey Stick Mesogens of Liquid Crystals." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/47285233061336910665.
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碩士<br>大同大學<br>化學工程學系(所)<br>97<br>Hockey stick mesogens were constructed by attaching flexible chains laterally (at meta-position) to a rod-like mesogenic core—3-hydroxyphenyl 4’-alkyloxy biphenyl-4-carboxylate. While the para-positioned chain were varied from octyloxy to dodecyloxy in length, the meta-positioned chains, hexyloxy and octyloxy (series III and IV), were replaced with nonafluorohexyloxy and tridecafluorooctyloxy chains (series I and II), respectively. The obtained mesogens and mesophases were studied with optical polarizing microscopy (OPM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and electric field effect.
Mesophases of smectic A (SmA), smectic C (SmC) and anticlinic smectic Ca (SmCa) were observed for the non-fluoro-derivatives, and only SmA and SmC were observed for the fluoro-derivatives. The OPM observation showed that the textures of SmA and SmC resemble those of rod-like mesogens, but occasionally with 2-brush defects in the schlieren textures of SmC. For the SmCa phase, the schlieren texture was dominated with 2-brush defects and the focal conic fans were overlapped with equal-distant parallel lines. The DSC study showed that the phase transitions of SmA-SmC and SmC-SmCa were all weakly first-order. Preliminary XRD results showed that these smectic phases were monolayer structure, and only very small layer contraction across the SmA-SmC transition was observed.
Elongated domains were observed for SmC and SmCa phases of these compounds in liquid crystal cell with surfaces treated for parallel alignments, 2μ thickness. The neighboring domains exchanged their dark and light appearance when the sample was rotated to opposite direction, but remained unchanged with inversion of the polarity of electric field. The SmCa phase exhibited similar behavior except that the parallel lines across the domains would gradually disappear with increasing field strength. The polarization of these smectic phases remain to be studied.
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Lung, Chin-Chang, and 龍志漳. "The synthesis and property of “hockey stick” shaped mesogens:ester derivatives of 3-alkyloxy benzoic acid." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/12217982831063217526.
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碩士<br>淡江大學<br>化學學系<br>92<br>A rigid core consisting of four phenyl rings connected by three ester functional groups at the para-positions has been used for making mesogenic derivatives. Typical calamitic mesogen with wide mesophase range is obtained when the flexible alkyloxy chains are attached at the para-positions of the ending rings. A hockey stick, or bent, shaped molecule is obtained when one of the alkyloxy chains is connected at the meta-position, Cn-m-Cm, and results in formation of anticlinic Smectic C (SmCA) in addition to SmC, SmA and N phases.
The mesophase-molecular structure relationship has been studied by varying the length of both the meta- and para-hydrocarbon chains, Cn and Cm, respectively. Occurrence of SmCA is more favorable for derivatives having shorter meta-chains: for n=4, SmCA phases are observed for derivatives with m=7 to 14, and for n=12 no SmCA phase is observed with the same m values.
Variation of the aromatic core is also conducted: (1) attach a methoxy group at the ortha-position of the ending ring, Cn-ms-Cm; (2) reverse the direction of one of the ester linking groups, Cn-mA-Cm; (3) remove one of the rings, Cn-m-CmBA. Derivatives obtained with these modifications exhibit no SmCA phase.
Chiral mesogens are obtained by replacing the aliphatic chain of the meta- position of Cn-m-Cm with ethyl lactate. Mesophase sequences observed are I2-I1-N*-TGBA-SmA for derivatives having m=8 and 10, and I2-I1-N*-UTGBC for m=12 and 14. Peculiar phase transition of iso to iso is observed for all these derivatives, along with the occurrence of TGB indicate that the twisting power is stronger for the hockey stick molecules as compared to the rod-like analogues.
The present study is carried out by optical polarizing microscopy, differential scanning calorimetry, powder X-ray diffraction and electric-field effect.
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Huang, Szu-Chieh, and 黃思捷. "Study on the Mesophases and Electro-optical Properties of Hockey-stick Mesogens Possessing Optically Active Chiral Group." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/32279093275739775000.
Full textAbstract:
碩士<br>大同大學<br>化學工程學系(所)<br>98<br>There are many factors affect the properties of ferroelectric chiral smectic C phase such as chiral group, core structure, linking group, terminal chain length and optical purity in rod-like chiral liquid crystals. The purpose of this research is looking for a better understanding the relationship between molecular structure and mesomorphic properties by changing the molecular architecture from rod-like to hockey-stick.
Thus, new non-fluorinated and semi-fluorinated chrial alcohols, (S)-1-butyloxy-2-propanol, (S)-1-(2,2,3,3,4,4,4-heptafluorobutyloxy)-1-propanol, and (S)-1-(2,2,2- trifluoroethoxy)-2-propanol, were designed and synthesized by the reaction of (S)-(-)-propylene oxide with alcohols under the base condition. These alcohols were then connected to the meta-position of phenyl ring in the compounds by the ester linkage to form compounds I(m,CH2CH2CH3), II(m, CF2CF2CF3) and III(m, CF3). (S)-1-(2,2,3,3,4,4,4-Heptafluorobutyloxy)-1-propanol was connected to the meta-position of phenyl ring in the compounds by the ether linkage to produce compounds IV(m, CF2CF2CF3).
The mesomorphic phases and their corresponding phase transition temperatures were determined by the polarizing microscopic texture and DSC thermograms. The results show the non-fluorinated liquid crystal materials posses SmA* and SmC* phases, and the semi-fluorinated liquid crystal materials enhance the thermal stability of smectic phases. In addition, as the semi-fluorinated chiral alkyl chain at chiral tail extending from -CF3 to -CF2CF2CF3 favors the formation and thermal stability of SmC* phase.
The results also show that compounds having ether linkage (IV(m=8-12)) at m=12 posses SmA* and unidentified SmX1* phases, and at m=8-11 posses SmA* and unidentified SmX1* and SmX2* phases. The electric field driven activities show that compounds IV(m) can be switched in SmX1* and SmX2* phases by the dc field, but the measurements of switching behavior and dielectric constants ε′ can not provide evidence for the existing ferroelectricity or antiferroelectricity in SmX1* and SmX2* phases.
The physical properties such as switching current, dielectric constant, spontaneous polarization, and optical tilt angle in the ferroelectric SmC* phase of chiral compounds were measured. The maximum magnitudes of the spontaneous polarization for compounds I(m=8-12), II(m=8-12), and III(m=7,10,12) are approximately in a range of 12.02-18.30 nC/cm2. Comparing rod-like compounds to hockey-stick compounds that possessing the same non-fluorinated chiral group show that there have nearly the same magnitudes of the maximum Ps value. But when comparing rod-like compounds to hockey-stick compounds that possessing the same semi-fluorinated chiral group show that the hokey-stick compounds have much lower magnitudes of the maximum Ps value. Changing the linking group from ester to ether, the Ps value was suppressed.
The maximum optical tilt angle of compounds I(m=8-12), II(m=8-12), and III(m=7,10,12) are approximately in a range of 26-38°. The results show that compounds in non-fluorinated and semi-fluorinated chiral group have nearly the same maximum optical tilt angle of chiral group. Comparing rod-like compounds to hockey-stick compounds show that the maximum apparent tilt angle of hockey-stick compounds are larger than that of rod-like compounds.
In conclusion, our results indicate that the hockey-stick chiral compounds having fluorinated chiral alkyl chain enhance the thermal stability of smectic phase, especially SmC* phase. It is interesting to find that two chiral smectic phases: SmX1* and SmX2* phases in compounds IV(m=8-12). There has no evidence to prove the existence of ferroelectricity or antiferroelectricity in SmX1* and SmX2* phase.
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Rovný, Lukáš. "Efektivita střelby přenesená z tréninkového procesu do utkání." Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-387854.
Full textAbstract:
Title: Efficiency of shooting transferred from the training process to a match Objectives: The diploma thesis is focusing on gathering information about shooting in ice hockey, creating excercises, two training units for shooting and then evaluating collected statistics on shooting from the whole season of one youth team. Attention will be given to a comparison of the productivity and efficiency of the shooting in order to find out how useful the invented exercises had been to improve shooting throughout the season. Methods: The diploma thesis uses experimental methods in order to incorporate fictional exercises to the training process. Consequently statistics that were collected throughout the season were used to check whether the increase in productivity and shooting efficiency was positive. Results: The considered set was separand by the selected statistics into three time periods. The subsequent comparison led to an increase in productivity and efficiency during the whole season. Key words: shooting, hockey stick, ice hockey, pass, match, puck