Development and validation of a hybrid-computer simulator for a transonic cryogenic wind tunnel

A study was undertaken to model the cryogenic wind tunnel process, to validate the model by the use of experimental data from the Langley 0.3 Meter Transonic Cryogenic Tunnel, and to construct an interactive simulator of the cryogenic tunnel using the validated model. Additionally, this model was used for designing closed loop feedback control laws for regulation of temperature and pressure in the 0.3 meter cryogenic tunnel. The global mathematical model of the cryogenic tunnel that were developed consists of coupled, nonlinear differential governing equations based on an energy state concept of the physical cryogenic phenomena. Process equations and comparisons between actual tunnel responses and computer simulation predictions were examined. Also included are the control laws and simulator responses obtained using the feedback schemes for closed loop control of temperature and pressure were also included

Effect of gyro verticality error on lateral autoland tracking performance for an inertially smoothed control law

The results of a simulation study performed to determine the effects of gyro verticality error on lateral autoland tracking and landing performance are presented. A first order vertical gyro error model was used to generate the measurement of the roll attitude feedback signal normally supplied by an inertial navigation system. The lateral autoland law used was an inertially smoothed control design. The effect of initial angular gyro tilt errors (2 deg, 3 deg, 4 deg, and 5 deg), introduced prior to localizer capture, were investigated by use of a small perturbation aircraft simulation. These errors represent the deviations which could occur in the conventional attitude sensor as a result of the maneuver-induced spin-axis misalinement and drift. Results showed that for a 1.05 deg per minute erection rate and a 5 deg initial tilt error, ON COURSE autoland control logic was not satisfied. Failure to attain the ON COURSE mode precluded high control loop gains and localizer beam path integration and resulted in unacceptable beam standoff at touchdown

City specific ‘racial threat’ can push neighborhood resources,like supermarkets, away from African Americans

Neighborhood resources – and areas with limited access to fresh produce (‘food deserts’) in particular – are important forms of inequality associated with the health outcomes of neighborhood residents. Applying ‘minority competition’ theory to neighborhood resource disparities, Jarrett Thibodeaux finds that the percentage of African Americans in a U.S. city predicts the placement of supermarkets near African Americans within the city. Other neighborhood resource disparities suffered by racial minorities may be caused by the ‘perceived threat to resources’ that a growing racial minority can provoke in the racial majority

A Eutrophication Model of the White River Basin Above Beaver Reservoir in Northwest Arkansas

With national interest focused on man’s ever increasing degradation of the waters in this nation, it is clearly evident that an accurate assessment of all parameters influencing water quality needs to be made. Moreover, nutrient levels and budgets reflecting eutrophication trends are important parameters in the overall factors effecting water quality in lakes and reservoirs. The ability to predict future eutrophication levels will greatly enhance the retardation of the eutrophication process. Through mathematical simulation of this process, eutrophication can be analyzed and intelligent decisions regarding water quality management can be made

Student Perceptions of Enhancing the Internship Experience for Online Principal Preparation Programs

Principal preparation programs understand the need for relevant internship activities that bridge the gap between theory and practice (Anast-May, Buckner, & Geer, 2011; Darling-Hammond, LaPointe, Meyerson, Orr, & Cohen (2007). Principal preparation programs utilizing distance technology are also charged with meeting this expectation and the electronic learning technologies have changed learning from restrictive to flexible, accessible, and innovative (Tseng & Gardner, 2016). The internship is a widely accepted program component of principal preparation that provides the student with actual administrative experience during the certification process; however, despite the mandates from national accreditation organizations and state certification agencies, the literature is replete with criticisms concerning the effectiveness of the internship experience (Cheney & Davis, 2011; Darling-Hammond et al., 2007; Fry, Bottoms, & O’Neill, 2005; Perez et al., 2011). Limited data in the form of student feedback, especially as it pertains to learner perceptions of the internship experience, have been collected (Gordon, Oliver, & Solis, 2016). According to Thiede (2012), it is important for faculty to seek out and study what students are thinking and saying about online education as most higher education institutions’ future enrollments may be predicated upon quality online courses

Psoriasis Vulgaris Successfully Treated with Goeckerman Treatment at Home: A Patient and Physician's Experience.

Goeckerman therapy is a highly effective treatment regimen for moderate-to-severe psoriasis. It involves regular exposure to ultraviolet B radiation and the application of crude coal tar. To our knowledge, only three centers in the USA currently offer a formal Goeckerman therapy treatment program; thus, access to this therapy is geographically limited. In this article, a motivated patient discusses his experience with generalized plaque psoriasis. This patient, while living in a Goeckerman-inaccessible area, deferred treatment with biologics and outpatient phototherapy to develop a modified Goeckerman regimen for at-home use. This home regimen, which did not involve the use of prescription-strength medications, resulted in full clearance of his psoriasis. We also discuss the patient's case from the perspective of a dermatology treatment team that has reviewed his experience

Flight investigation of manual and automatic VTOL decelerating instrument approaches and landings

A flight investigation was undertaken to study the problems associated with manual and automatic control of steep, decelerating instrument approaches and landings under simulated instrument conditions. The study was conducted with a research helicopter equipped with a three-cue flight-director indicator. The scope of the investigation included variations in the flight-director control laws, glide-path angle, deceleration profile, and control response characteristics. Investigation of the automatic-control problem resulted in the first automated approach and landing to a predetermined spot ever accomplished with a helicopter. Although well-controlled approaches and landings could be performed manually with the flight-director concept, pilot comments indicated the need for a better display which would more effectively integrate command and situation information

Acrodermatitis continua of Hallopeau: clinical perspectives.

Acrodermatitis continua of Hallopeau (ACH) is a rare, sterile pustular eruption of one or more digits. The condition presents with tender pustules and underlying erythema on the tip of a digit, more frequently arising on a finger than a toe. As far as classification, ACH is considered a localized form of pustular psoriasis. The eruption typically occurs after local trauma or infection, but such a history is not always present and various other etiologies have been described including infectious, neural, inflammatory, and genetic causes. The natural progression of ACH is chronic and progressive, often resulting in irreversible complications such as onychodystrophy that can result in anonychia, as well as osteitis that can result in osteolysis of the distal phalanges. Because of the rarity of ACH, there have been no randomized controlled studies to evaluate therapies, resulting in an absence of standardized treatment guidelines. In clinical practice, a wide variety of treatments have been attempted, with outcomes ranging from recalcitrance to complete resolution. In recent years, the introduction of biologics has provided a new class of therapy that has revolutionized the treatment of ACH. Specifically, rapid and sustained responses have been reported with the use of anti-tumor necrosis factor agents like infliximab, adalimumab, and etanercept; IL-17 inhibitors like secukinumab; IL-12/23 inhibitors like ustekinumab; and IL-1 inhibitors like anakinra. Nevertheless, there remains a considerable need for more research into treatment for the benefit of individual patients with ACH as well as for the clinical knowledge gained by such efforts. The purpose of this review is to provide a comprehensive overview of the key features of ACH as well as a discussion of clinical management strategies for this unique and debilitating condition

Emerging Methods to Objectively Assess Pruritus in Atopic Dermatitis.

INTRODUCTION:Atopic dermatitis (AD) is an inflammatory skin disease with a chronic, relapsing course. Clinical features of AD vary by age, duration, and severity but can include papules, vesicles, erythema, exudate, xerosis, scaling, and lichenification. However, the most defining and universal symptom of AD is pruritus. Pruritus or itch, defined as an unpleasant urge to scratch, is problematic for many reasons, particularly its negative impact on quality of life. Despite the profoundly negative impact of pruritus on patients with AD, clinicians and researchers lack standardized and validated methods to objectively measure pruritus. The purpose of this review is to discuss emerging methods to assess pruritus in AD by describing objective patient-centered tools developed or enhanced over the last decade that can be utilized by clinicians and researchers alike. METHODS:This review is based on a literature search in Medline, Embase, and Web of Science databases. The search was performed in February 2019. The keywords were used "pruritus," "itch," "atopic dermatitis," "eczema," "measurements," "tools," "instruments," "accelerometer," "wrist actigraphy," "smartwatch," "transducer," "vibration," "brain mapping," "magnetic resonance imaging," and "positron emission tomography." Only articles written in English were included, and no restrictions were set on study type. To focus on emerging methods, prioritization was given to results from the last decade (2009-2019). RESULTS:The search yielded 49 results in PubMed, 134 results in Embase, and 85 results in Web of Science. Each result was independently reviewed in a standardized manner by two of the authors (M.S., K.L.), and disagreements between reviewers were resolved by consensus. Relevant findings were categorized into the following sections: video surveillance, acoustic surveillance, wrist actigraphy, smart devices, vibration transducers, and neurological imaging. Examples are provided along with descriptions of how each technology works, instances of use in research or clinical practice, and as applicable, reports of validation studies and correlation with other methods. CONCLUSION:The variety of new and improved methods to evaluate pruritus in AD is welcomed by clinicians, researchers, and patients alike. Future directions include next-generation smart devices as well as exploring new territories, such as identifying biomarkers that correlate to itch and machine-learning programs to identify itch processing in the brain. As these efforts continue, it will be essential to remain patient-centered by developing techniques that minimize discomfort, respect privacy, and provide accurate data that can be used to better manage itch in AD