Waterfront construction in New York Harbor

The following chapters are devoted to the various phases of that branch of construction which is followed from the offshore side of the waterfront. This branch, in the parlance of the building trades, is known as dockbuilding. Years ago all waterfront structures in New York Harbor were constructed almost entirely of timber and experience taught that the most economical approach for building docks and wharves was made by utilizing floating piledrivers and derricks. Thus it happened that dockbuilders became skilled both in the use of wood framing tools and in handling marine equipment. Modern dockbuilders must have, in addition to those skills, the ability to build forms for concrete construction, handle steel and concrete piling, and operate mechanical labor saving devices. It is recognized that, in the construction of modern waterfront facilities, dockbuilding is not the only trade represented. The ironworkers, masons, metalsmiths, and so forth however, may ply their trades in any location, whereas dockbuilding is a specialty confined to the waterfront. Were it not for the act that portions of it include such other operations as dredging, subaqueous pipe and cable laying, and diving, this text might have been appropriately entitled Dockbuilding rather than Waterfront Construction. The problems that confront the promoters and designers of waterfront facilities have not been considered to any great extent and it has been attempted to describe in the chapters that follow only the various types and methods of construction peculiar to the waterfront, together with the materials, plant, and labor required for them. While the subject of waterfront construction is far from being exhausted in the following chapters, the more important kinds of facilities, types of construction and varieties of plant prevalent in New York Harbor have, in varying degrees of detail, been described. Chapter One may, at first, seem to digress considerably, but it is believed that the incidental information contained therein may prove of interest to someone unfamiliar with historical geology. The latter part of the chapter will be found to contain more pertinent information. In the second chapter, as In the first, there will be found paragraphs not closely pertaining to the subject of construction. They have nevertheless been included because a broader background for the chapters that follow is thus provided. In gathering some of the material assembled herein the services provided by the Public Libraries of Newark, New Jersey, and New York City, the Engineering Societies Library, and the American Museum of Natural History were utilized. Some of the information, not to be found in books and many of the photographs with which the text is illustrated, were generously contributed by a number of organizations whose representatives were considerate enough to give some of their own valuable time to be of assistance. Particularly helpful in this respect were: United States Corps of Engineers United States Coast and Geodetic Survey United States Geological Survey Port of New York Authority Tri Borough Bridge and Tunnel Authority New York City Department of Public Works New York City Board of Transportation Allen N. Spooner & Son, Inc. Morris & Cumings Dredging Co. Inc. Merritt Chapman & Scott Corporation Atlantic, Gulf Pacific Co. Massey Concrete Products Company National Association of River and Harbor Contractors McKiernan Terry Corporation Vulcan Iron Works Bucyrus Erie Company Ellicott Machine Corporation Superior Lidgerwood Mundy Corporation United States Pipe and Foundry Company Carnegie Illinois Steel Corporation McGraw Hill Publishing Company To both the individuals and organizations by whom time end material for this thesis was contributed the writer is indebted

Validation of the GUESS-18 for the Usability of a Virtual Reality Racing Game

Virtual reality (VR) technology has been in development for many decades, with recent strides in the consumer market. Head-mounted displays (HMDs) provide an immersive VR experience by inserting users into an artificially constructed digital world. However, there is currently no standardized tool for measuring the usability of a VR system or environment. The GUESS-18 is a validated usability questionnaire designed for measuring the usability of video games with 9 factors present in video games. The objective of this study was to validate the GUESS-18 for measuring the usability of VR in a gaming environment. Participants played Assetto Corsa, a racing game, with an HMD in VR and with a traditional monitor. The best lap times were recorded as a performance measure. Errors were also recorded, which included driving off the track or colliding with a wall. Users answered the GUESS-18 and the System Usability Scale (SUS) after their experience. They also answered the Simulator Sickness Questionnaire (SSQ) before and after using VR. Confirmatory Factor Analysis (CFA) was performed to determine the validity of the GUESS-18’s measurements for usability of the racing game in VR. The GUESS-18 is an accurate and effective tool for measuring usability of the game in VR. The Comparative Fit Index (CFI) and Root Mean Square Error of Approximation (RMSEA) values indicate appropriate model fit, with values of 0.967 and 0.056, respectively. VR yielded significantly faster lap times by about 5%. No other differences were found for performance. Usability scores from the GUESS-18 were significantly higher in the VR condition than the traditional monitor by about 6.4%. SSQ scores were significantly higher after engaging with VR by 282.5%. No differences were found for SUS scores between display conditions. We also found that playing the game in VR resulted in greater immersion and personal gratification than playing with the monitor. Future research should focus on the development and validation of a generalized VR usability tool that captures the latent factors when using a VR system

Predictions of the emergence of vaccine-resistant hepatitis B in The Gambia using a mathematical model

Vaccine escape variants of hepatitis B virus (HBV) have been identified world-wide. A mathematical model of HBV transmission is used to investigate the potential pattern of emergence of such variants. Attention is focused on The Gambia as a country with high quality epidemiological data, universal infant immunization and in which escape mutants after childhood infections have been observed. We predict that a variant cannot become dominant for at least 20 years from the start of vaccination, even when using a vaccine which affords no cross protection. The dominant factor responsible for this long time scale is the low rate of infectious contacts between infected and susceptible individuals (we estimate the basic reproduction number of hepatitis B in The Gambia to be 1·7). A variant strain that achieves high prevalence will also take many years to control, and it is questionable whether emergence will be identifiable by sero-surveillance until of high prevalence. The sensitivity of the model predictions to epidemiological and demographic factors is explored

Predictions of the emergence of vaccine-resistant hepatitis B in The Gambia using a mathematical model

Vaccine escape variants of hepatitis B virus (HBV) have been identified world-wide. A mathematical model of HBV transmission is used to investigate the potential pattern of emergence of such variants. Attention is focused on The Gambia as a country with high quality epidemiological data, universal infant immunization and in which escape mutants after childhood infections have been observed. We predict that a variant cannot become dominant for at least 20 years from the start of vaccination, even when using a vaccine which affords no cross protection. The dominant factor responsible for this long time scale is the low rate of infectious contacts between infected and susceptible individuals (we estimate the basic reproduction number of hepatitis B in The Gambia to be 1·7). A variant strain that achieves high prevalence will also take many years to control, and it is questionable whether emergence will be identifiable by sero-surveillance until of high prevalence. The sensitivity of the model predictions to epidemiological and demographic factors is explored

Mandated Marketing Programs For California Commodities

Agricultural and Food Policy, Marketing,

Magneto-Optic Field Coupling in Optical Fiber Bragg Gratings

The invention is a magneto-optic coupled magnetic sensor that comprises a standard optical fiber Bragg grating system. The system includes an optical fiber with at least one Bragg grating therein. The optical fiber has at least an inner core and a cladding that surrounds the inner core. The optical fiber is part of an optical system that includes an interrogation device that provides a light wave through the optical fiber and a system to determine the change in the index of refraction of the optical fiber. The cladding of the optical fiber comprises at least a portion of which is made up of ferromagnetic particles so that the ferromagnetic particles are subject to the light wave provided by the interrogation system. When a magnetic field is present, the ferromagnetic particles change the optical properties of the sensor directly

Analysis of western lowland gorilla (Gorilla gorilla gorilla) specific Alu repeats

Background: Research into great ape genomes has revealed widely divergent activity levels over time for Alu elements. However, the diversity of this mobile element family in the genome of the western lowland gorilla has previously been uncharacterized. Alu elements are primate-specific short interspersed elements that have been used as phylogenetic and population genetic markers for more than two decades. Alu elements are present at high copy number in the genomes of all primates surveyed thus far. The AluY subfamily and its derivatives have been recognized as the evolutionarily youngest Alu subfamily in the Old World primate lineage. Results: Here we use a combination of computational and wet-bench laboratory methods to assess and catalog AluY subfamily activity level and composition in the western lowland gorilla genome (gorGor3.1). A total of 1,075 independent AluY insertions were identified and computationally divided into 10 subfamilies, with the largest number of gorilla-specific elements assigned to the canonical AluY subfamily. Conclusions: The retrotransposition activity level appears to be significantly lower than that seen in the human and chimpanzee lineages, while higher than that seen in orangutan genomes, indicative of differential Alu amplification in the western lowland gorilla lineage as compared to other Homininae. © 2013 McLain et al.; licensee BioMed Central Ltd

Analysis of western lowland gorilla (Gorilla gorilla gorilla) specific Alu repeats

Abstract Background Research into great ape genomes has revealed widely divergent activity levels over time for Alu elements. However, the diversity of this mobile element family in the genome of the western lowland gorilla has previously been uncharacterized. Alu elements are primate-specific short interspersed elements that have been used as phylogenetic and population genetic markers for more than two decades. Alu elements are present at high copy number in the genomes of all primates surveyed thus far. The AluY subfamily and its derivatives have been recognized as the evolutionarily youngest Alu subfamily in the Old World primate lineage. Results Here we use a combination of computational and wet-bench laboratory methods to assess and catalog AluY subfamily activity level and composition in the western lowland gorilla genome (gorGor3.1). A total of 1,075 independent AluY insertions were identified and computationally divided into 10 subfamilies, with the largest number of gorilla-specific elements assigned to the canonical AluY subfamily. Conclusions The retrotransposition activity level appears to be significantly lower than that seen in the human and chimpanzee lineages, while higher than that seen in orangutan genomes, indicative of differential Alu amplification in the western lowland gorilla lineage as compared to other Homininae.http://deepblue.lib.umich.edu/bitstream/2027.42/112762/1/13100_2013_Article_86.pd