590 research outputs found

    Study in Urban Geography: An Evaluation of Economic and Industrial Development in Windsor 1945-1987

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    Growth and change of cities and towns has always been of great interest to geographers. Growth of municipalities varies widely with the type of urban areas themselves and their geographic location. Many variable come together to form the cities we have today. These variables can be government influence, technology, natural resources, climate, and physiography. This thesis will assess economic development policies of the city of Windsor. Primary concern will be given to sectoral diversification policy, new aggressive policy, and intra-manufacturing diversification.https://scholar.uwindsor.ca/undergraduate-major-papers/1007/thumbnail.jp

    New Zealand contributions to the global earthquake model’s earthquake consequences database (GEMECD)

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    The Global Earthquake Model’s (GEM) Earthquake Consequences Database (GEMECD) aims to develop, for the first time, a standardised framework for collecting and collating geocoded consequence data induced by primary and secondary seismic hazards to different types of buildings, critical facilities, infrastructure and population, and relate this data to estimated ground motion intensity via the USGS ShakeMap Atlas. New Zealand is a partner of the GEMECD consortium and to-date has contributed with 7 events to the database, of which 4 are localised in the South Pacific area (Newcastle 1989; Luzon 1990; South of Java 2006 and Samoa Islands 2009) and 3 are NZ-specific events (Edgecumbe 1987; Darfield 2010 and Christchurch 2011). This contribution to GEMECD represented a unique opportunity for collating, comparing and reviewing existing damage datasets and harmonising them into a common, openly accessible and standardised database, from where the seismic performance of New Zealand buildings can be comparatively assessed. This paper firstly provides an overview of the GEMECD database structure, including taxonomies and guidelines to collect and report on earthquake-induced consequence data. Secondly, the paper presents a summary of the studies implemented for the 7 events, with particular focus on the Darfield (2010) and Christchurch (2011) earthquakes. Finally, examples of specific outcomes and potentials for NZ from using and processing GEMECD are presented, including: 1) the rationale for adopting the GEM taxonomy in NZ and any need for introducing NZ-specific attributes; 2) a complete overview of the building typological distribution in the Christchurch CBD prior to the Canterbury earthquakes and 3) some initial correlations between the level and extent of earthquake-induced physical damage to buildings, building safety/accessibility issues and the induced human casualtie

    Endogas da metano e corretta sinterizzazione di acciai

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    Prima di spiegare il significato del termine corretto, in questo contesto, si espongono le influenze delcarbonio su microstrutture e proprietà degli acciai compatti. Le conoscenze metallurgiche di base hannoevidenziato che le proprietà ottimali dipendenti dalle aggiunte di lega si possono ottenere solo medianteun controllo preciso del contenuto di carbonio. Un confronto tra le tolleranze sul contenuto di C degliacciai completamente densi e quelle ammesse negli acciai sinterizzati è molto sfavorevole per lametallurgia delle polveri. Indipendentemente da questo paragone, un controllo preciso del contenuto dicarbonio è sempre un fattore critico per garantire sistematicamente delle proprietà meccaniche elevate.Si esaminano i vincoli termodinamici sugli equilibri del carbonio durante la sinterizzazione e si discutonole interazioni possibili tra l'acciaio ed un’atmosfera controllata di endogas da metano. La valutazionedelle proprietà fisiche dei singoli gas, a varie temperature, mostra che i loro comportamenti ed i loroeffetti possono essere molto differenti. Alcuni costituenti gassosi possono causare diminuzione oarricchimento in carbonio, mentre altri non modificano gli equilibri. Nel caso di scambi chimici, durantela sinterizzazione, che coinvolgono il carbonio, il profilo di temperatura in alcune zone del forno puòessere un fattore critico. Si analizzano infine alcuni schemi tipici di forni di sinterizzazione e se neapprofondiscono le possibilità d’impiego per la corretta elaborazione di acciai e per il preciso controllodel carbonio, delle microstrutture, delle proprietà meccaniche

    CRITERI DI CLASSIFICAZIONE DEL GRADO DI COMPLICAZIONE DELLE FORME DEI COMPONENTI SINTERIZZATI

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    Per agevolare la comprensione dei criteri in base ai quali classificare le difficoltà di forma di com-ponenti meccanici sinterizzati si premettono delle indicazioni di base sulla formatura mediante pressatura entro stampi rigidi di miscele di polveri metalliche. L’aumento di densità apparente, dal valore tipico della polvere in riempitura, versata per gravità nella cavità dello stampo, a quello raggiunto alla fine dell’addensamento, consente di ottenere corpi coerenti di forma definita. Poiché il comportamento delle polveri sottoposte a pressione differisce sostanzialmente da quello dei li-quidi, nel caso di particolari che presentano spessori diversi nel senso della pressatura è necessa-rio suddividere idealmente le forme in prismi, ognuno individuato da una determinata altezza. Per ogni prisma così individuato lo stampo deve idealmente presentare una coppia di punzoni. In ogni prisma, inoltre l’addensamento deve tendenzialmente essere bilaterale, simmetrico e simultaneo. Il numero di spessori in senso assiale, pertanto, costituisce un elemento di base per la classificazione delle difficoltà di forma. Al contrario, a differenza delle lavorazioni competitive, le caratteristiche dei profili dei pezzi in pianta non hanno peso significativo sulla valutazione delle complicazioni di forma: un ingranaggio con foro scanalato ed una semplice bussola cilindrica appartengono alla stessa categoria. Si presenta poi una serie di pezzi, suddivisi per grado di difficoltà. L’immissione sul mercato di presse multipiastra a controllo numerico ha reso più agevole e controllabile la for-matura di pezzi di geometria complicata con caratteristiche fisico-geometriche costanti. In questo modo, anche le proprietà meccaniche dei sinterizzati rispettano le necessarie esigenze di qualità

    Sea Level Changes Affect Seismicity Rates in a Hydrothermal System Near Istanbul

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    Small stress changes such as those from sea level fluctuations can be large enough to trigger earthquakes. If small and large earthquakes initiate similarly, high-resolution catalogs with low detection thresholds are best suited to illuminate such processes. Below the Sea of Marmara section of the North Anatolian Fault, a segment of urn:x-wiley:00948276:media:grl65397:grl65397-math-0001150 km is late in its seismic cycle. We generated high-resolution seismicity catalogs for a hydrothermal region in the eastern Sea of Marmara employing AI-based and template matching techniques to investigate the link between sea level fluctuations and seismicity over 6 months. All high resolution catalogs show that local seismicity rates are larger during time periods shortly after local minima of sea level, when it is already rising. Local strainmeters indicate that seismicity is promoted when the ratio of differential to areal strain is the largest. The strain changes from sea level variations, on the order of 30–300 nstrain, are sufficient to promote seismicity

    MWNT Surface Self-Assembling in Fire Retardant Polyethylene-Carbon nanotubes nanocomposites

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    Multiwall carbon nanotubes (MWNT) were melt blended at different concentration with linear low density polyethylene (LLDPE). The nanotubes impart the fire-retardant characteristics to the polymer by formation of a thin protective film of MWNT/carbon char generated on the surface of the nanocomposites. The film formation mechanism is discussed

    Experimental Investigation on Thermal Diffusivity of PM Steels

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    The scanty literature data on thermal diffusivity of P/M steels seems contradictory, if the cooling speed on quenching is the evaluation parameter. Due to the basic importance of diffusivity on the response of P/M steels to heat-treating, an experimental survey has been carried out, to collect data on various P/M steels, based on prealloyed, or diffusion-bonded, or admixed powders. The study has also covered the influence of processing parameters, such as compaction pressure and sintering temperature. The flash method has been used to measure the thermal diffusivity of P/M steels. This method directly measures the thermal diffusivity of a sample in slab shape. A plane-parallel sample is inserted in the test apparatus and then a short light pulse, produced by a laser or a flash lamp, heats the front surface of the sample. The heat diffuses through the sample, leading to a temperature rise on the sample rear surface. An infrared detector measures this temperature rise, versus time, and thermal diffusivity is derived from the least square regression on the whole temperature trend, using the analytical solution of heat conduction. The results show that thermal diffusivity increases as density increases. This achievement can be justified by a simple theoretical analysis of the thermal conductivity on thermal diffusivity. The collected data also enable us to ascertain the influence of sintered material composition and carbon content on thermal diffusivity. The results should contribute to clarify some uncertainties and perplexities on the behavior of properly elaborated P/M steels, to be hardened by heat treatment, conventional – such as oil quenching – or innovative, such as sinter -hardening

    Influence of process parameters and alloying type on properties of laser quenched PM-steels

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    Different alloyed PM steels have been laser quenched in industrial equipment laser diodes (4 kW, controlled by material surface temperature). The aim of this work is to investigate their responses to different process condition and different alloying metals, i.e. Cu, Ni, Mo, Cr and C. Furthermore the microstructure of hardened layer, heat affected zone (HAZ) and bulk zone Pre-alloyed, diffusion bonded and hybrid raw materials have been used. Design of Experiments has been the approach for evaluating the effect of treatment parameters (i.e temperature, spot size and speed) and to develop predictive models, correlating such parameters to hardening depth and scratch hardness number. Results demonstrated which valuable properties could be achieved, even through relatively low alloying. The promising results are encouraging since they allow to forecast a possible positive combination of high local hardness and wear resistance of high precision PM part
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