Helium tables.

These tables are intended to provide a standard method and to facilitate the calculation of the quantity of "Standard Helium" in high pressure containers. The research data and the formulas used in the preparation of the tables were furnished by the Research Laboratory of Physical Chemistry, of the Massachusetts Institute of Technology

Some factors affecting the use of lighter than air systems

The uses of lighter-than-air vehicles are examined in the present day transportation environment. Conventional dirigibles were found to indicate an undesirable economic risk due to their low speeds and to uncertainties concerning their operational use. Semi-buoyant hybrid vehicles are suggested as an alternative which does not have many of the inferior characteristics of conventional dirigibles. Economic and performance estimates for hybrid vehicles indicate that they are competitive with other transportation systems in many applications, and unique in their ability to perform some highly desirable emergency missions

A semibuoyant vehicle for general transportation missions

The concept of a small, semibuoyant, lifting-body airship with either a disposable or nondisposable buoyant fluid is discussed. Estimations of fuel consumption, payload capability, power requirements and productivity are made and compared to other flight systems. Comparisons are made on the basis of equal cost vehicles. The assumption is made that, to a first-order approximation, the costs of developing, procuring, and operating a commercial air transport vehicle are proportional to vehicle empty weight. It must be noted that no historical cost data exist for the lifting-body airship and therefore these comparisons must be considered preliminary

Critical Consciousness-Raising: High School Teachers\u27 Collective Strategies to Engage Students\u27 Inspiragination

This study is a collection of strategies and practices utilized by ten high school teachers to inspire their students to engage with their critical consciousness as well as think critically about the world and their lived realities. Through this research, the study seeks to better understand how high school teachers create environments within their classrooms in which students question what exists, reflect on their own identities relative to the world, and engage in inspiragination. To examine this, 10 semi-structured, in-depth interviews with high school teachers were conducted via phone or Zoom. After cross-analyzing the interview transcripts, 10 themes arose relative to teachers encouraging their students to engage with their critical consciousness. These include, but are not limited to, 1) teachers should cultivate content so that students find it relevant to their lives 2) there should be effort, energy, and intention placed into building relationships with one’s students 3) don’t be afraid to share your story 4) the physical layout of the learning environment should be humanizing 5) life is contradictory and complex: teach it that way 6) psychological and physical safety should be a top priority 7) approaches to discipline and utilizing your real and assumed power 8) teaching as a political act? 9) these things may burn you out: here’s what they are and some mitigation strategies 10) inspiragination: a fluid concept. Additionally, the findings suggest that teaching is not ‘perfect-able’ – while one can implement and be cognizant of these themes, strategies, and practices (and more!), it is important to recognize that your own unique being combined with a particular group of students is not replicable... so go get ‘em

Adolescent Female Embodiment As A Transformational Experience In The Lives of Women: An Empirical Existential-Phenomenological Investigation

Adolescence can be a time of psychological vulnerability in the life cycle of a woman as she experiences multiple developmental changes. As articulated in the literature related to adolescent female development, a changing body may be at the heart of what can make this a time of profound transition for the adolescent girl as she attempts to negotiate alterations in her identity and self-concept, and consequently her social roles. The purpose of this investigation of adolescent female embodiment was to understand the experience of adolescent girls as it relates to their changing bodies, and to explore the question of whether these experiences put them at risk for limitations and a loss of potential in their lives as adult women. Specifically, this investigation examined the vulnerability of the adolescent girl, as identified by Pipher, to a loss of wholeness, self-confidence, and self-direction that may continue into adulthood. The means for illuminating these existential possibilities involved asking adult women to reflect upon and describe their experiences of adolescent bodily change in terms of how these changes had affected their view of themselves, their relationships with others, and their everyday lives, as well as the ways in which these experiences had affected their lives since adolescence. The findings of this study of adolescent female embodiment indicate a profound unity between the body and the self, and supports previous research suggesting a strong unity between body image and self-concept in this population. Strong connections between alterations in the body/self and changes in familial and social relationships were also articulated by the participants of this study. Relationships cited as being most significantly affected, were those with their mothers, whom they felt had not prepared them for what was to come, and their relationships with male and female peers which were altered in relation to this new sense of confusion or lack of self-assuredness. The participants of the study also universally described their awareness of their bodies becoming objects in the world, and the limitations that this increased self-consciousness placed upon them and their freedoms. This investigation also identified individual struggles that the participants continue to engage in as adult women, struggles that involve developing a sense of autonomy and authenticity, and struggles to reclaim the self. The results of this investigation are relevant for clinical assessment and intervention with adolescent girls and women as they make explicit some of the multiple losses and ransitions that make them potentially vulnerable to anxiety and depression, and which must be successfully negotiated by this population

Transport Materials

The purpose of this experimental project was to design, construct, and validate a high-resolution apparatus to measure thermal and electrical property changes in heat treatable aluminum alloys. The materials chosen that make up the apparatus were chosen based on properties for a 500 degree change that will isolate the sample material to give a one-directional thermal and electrical flow through the sample material. The goal was to measure the property changes from the development of precipitates forming due to artificial aging. Thermal resistance was measured at four different stages throughout the artificial aging process of wrought Aluminum 6061 and cast Aluminum 319 during a T6 temper. The design aimed to create an apparatus that can swap sample materials with ease

A longitudinal look at electronic mentoring relationships

Current advancements in information technology are increasingly impacting work relationships. Rapid technological changes have significant implications specifically for workplace mentoring because they may offer faster and more economical ways of building relationships. However, the e-mentoring literature is still evolving, and the extent to which e-mentoring parallels face-to-face mentoring is unknown. The purpose of this study was to investigate the development of mentoring functions over time and how the development varies depending on the amount and type of computer mediated communication. While career-support was greater at initial points in the relationship, psychosocial-support increased at a greater velocity for mentors. Bandwidth and percentage of face-to-face communication had no significant impact on mentoring functions. Result implications are discussed and directions for future research are proposed

Analysis of algorithms for online routing and scheduling in networks

We study situations in which an algorithm must make decisions about how to best route and schedule data transfer requests in a communication network before each transfer leaves its source. For some situations, such as those requiring quality of service guarantees, this is essential. For other situations, doing work in advance can simplify decisions in transit and increase the speed of the network. In order to reflect realistic scenarios, we require that our algorithms be online, or make their decisions without knowing future requests. We measure the efficiency of an online algorithm by its competitive ratio, which is the maximum ratio, over all request sequences, of the cost of the online algorithm\u27s solution to that of an optimal solution constructed by knowing all the requests in advance.;We identify and study two distinct variations of this general problem. In the first, data transfer requests are permanent virtual circuit requests in a circuit-switched network and the goal is to minimize the network congestion caused by the route assignment. In the second variation, data transfer requests are packets in a packet-switched network and the goal is to minimize the makespan of the schedule, or the time that the last packet reaches its destination. We present new lower bounds on the competitive ratio of any online algorithm with respect to both network congestion and makespan.;We consider two greedy online algorithms for permanent virtual circuit routing on arbitrary networks with unit capacity links, and prove both lower and upper bounds on their competitive ratios. While these greedy algorithms are not optimal, they can be expected to perform well in many circumstances and require less time to make a decision, when compared to a previously discovered asymptotically optimal online algorithm. For the online packet routing and scheduling problem, we consider an algorithm which simply assigns to each packet a priority based upon its arrival time. No packet is delayed by another packet with a lower priority. We analyze the competitive ratio of this algorithm on linear array, tree, and ring networks

Pleiotropic effects on cardiovascular risk factors within and between the fourth and sixth decades of life: Implications for genotype × age interactions

We used an approach for detecting genotype × environment interactions to detect and characterize genotype × age interaction in longitudinal measures of three well known cardiovascular risk factors: total plasma cholesterol (TC), systolic blood pressure (SBP), and body weight (Wgt). Our objectives were to determine if the same gene or suite of genes influences quantitative variation in each of these phenotypes in the 4(th )and 6(th )decades of life, to assess the impact of additive gene effects in these two decades, and to evaluate the stability of pleiotropic relationships among these phenotypes. Using the Framingham Heart Study data, we constructed two cross-sectional samples comprising individuals on whom these phenotypes were measured at ages 30-39 years (Original Cohort: exam 1, Offspring Cohort: exam 2) and at ages 50-59 years (Original Cohort: exam 11, Offspring Cohort: exam 5). We also constructed a longitudinal sample from the cross-sectional sample members for whom measures on these traits were available at both ages (i.e., 4(th )and 6(th )decades of life). Patterns of pleiotropy, inferred from genetic correlations between traits, differ between the two age classes. Further, additive genetic variance in SBP during the 4(th )decade of life is attributable to a different gene or suite of genes than during the 6(th). The magnitude of the effect increases for SBP. Variation in TC and Wgt appear to be influenced by the same gene or genes in both decades. The magnitude of the effect is stable for TC, but increases dramatically with age for Wgt