Integrated aerodynamic/dynamic optimization of helicopter rotor blades

An integrated aerodynamic/dynamic optimization procedure is used to minimize blade weight and 4 per rev vertical hub shear for a rotor blade in forward flight. The coupling of aerodynamics and dynamics is accomplished through the inclusion of airloads which vary with the design variables during the optimization process. Both single and multiple objective functions are used in the optimization formulation. The Global Criteria Approach is used to formulate the multiple objective optimization and results are compared with those obtained by using single objective function formulations. Constraints are imposed on natural frequencies, autorotational inertia, and centrifugal stress. The program CAMRAD is used for the blade aerodynamic and dynamic analyses, and the program CONMIN is used for the optimization. Since the spanwise and the azimuthal variations of loading are responsible for most rotor vibration and noise, the vertical airload distributions on the blade, before and after optimization, are compared. The total power required by the rotor to produce the same amount of thrust for a given area is also calculated before and after optimization. Results indicate that integrated optimization can significantly reduce the blade weight, the hub shear and the amplitude of the vertical airload distributions on the blade and the total power required by the rotor

Optimization methods applied to the aerodynamic design of helicopter rotor blades

Described is a formal optimization procedure for helicopter rotor blade design which minimizes hover horsepower while assuring satisfactory forward flight performance. The approach is to couple hover and forward flight analysis programs with a general-purpose optimization procedure. The resulting optimization system provides a systematic evaluation of the rotor blade design variables and their interaction, thus reducing the time and cost of designing advanced rotor blades. The paper discusses the basis for and details of the overall procedure, describes the generation of advanced blade designs for representative Army helicopters, and compares design and design effort with those from the conventional approach which is based on parametric studies and extensive cross-plots

Valuing Fed Cattle Using Slice Shear Force Measurements

Marketing fed cattle using grid pricing has become a popluar way to sell cattle. One of the most important beef characteristics, according to consumers, is beef tenderness. USDA quality grades are poor predictors of meat tenderness. However, mechanical shear force does objectively measure tenderness. This study illustrates how problematic USDA quality grades are at assessing accurate beef tenderness and proposes and evaluates a tenderness-based valuation system based on slice shear force technology. We show that cattle of all quality grades are substantially over- or under-valued when using a grid realtive to a tenderness-based valuation system.Marketing,

Valuing Fed Cattle Using Objective Tenderness Measures

Beef tenderness is critical in consumer satisfaction with beef steak products. Current fed cattle valuation systems do not differentiate carcasses based upon tenderness variation. However, considerable research indicates consumers are willing to pay more for tender relative to tough beef steak. This article develops a tenderness-augmentation to current fed cattle grid pricing systems. Using a large set of actual carcasses, we determine that a tenderness-augmented price grid would reorder fed cattle value by on average nearly $5.00/cwt dressed relative to current valuation methods. Substantial opportunity is present to improve beef tenderness through new price signals to producers.beef quality, meat tenderness, cattle value, cattle price, Agribusiness, Farm Management, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries, Q11, Q13, M31,

Determining significant parameters on health and well-being of building occupants towards re-engineered inclusive environment

People spend over 90% of their time in the buildings. A building is a place where people are spending more time doing activities, thus an inclusive environment of the buildings is very important to ensure that people are having a healthy life. An inclusive environment is important for the well-being of building occupants. Indoor environmental quality is one of the essential elements in creating an inclusive environment in which a poor quality of indoor environment affects the health of the occupants both physically and mentally, their performance, productivity, comfort, satisfaction, and well-being. Even though people are towards creating an inclusive environment but it is a limited study on the parameters of the inclusive environment. Thus, this paper is to study the parameters of the inclusive environment by focused on the element of the indoor environmental quality for building occupants based on literature reviews of articles between the year 2006 and 2016. Based on the content analysis, it has been discovered that there are various parameters of an inclusive environment which are visual comfort, thermal comfort, acoustic comfort, indoor air quality, buildings factors, occupants’ factors, and climate condition factors. The parameters can be very useful as guidelines and development of policy in providing inclusive environment for the healthy lifestyle of building occupants

Determining significant parameters on health and well-being of building occupants towards re-engineered inclusive environment

People spend over 90% of their time in the buildings. A building is a place where people are spending more time doing activities, thus an inclusive environment of the buildings is very important to ensure that people are having a healthy life. An inclusive environment is important for the well-being of building occupants. Indoor environmental quality is one of the essential elements in creating an inclusive environment in which a poor quality of indoor environment affects the health of the occupants both physically and mentally, their performance, productivity, comfort, satisfaction, and well-being. Even though people are towards creating an inclusive environment but it is a limited study on the parameters of the inclusive environment. Thus, this paper is to study the parameters of the inclusive environment by focused on the element of the indoor environmental quality for building occupants based on literature reviews of articles between the year 2006 and 2016. Based on the content analysis, it has been discovered that there are various parameters of an inclusive environment which are visual comfort, thermal comfort, acoustic comfort, indoor air quality, buildings factors, occupants’ factors, and climate condition factors. The parameters can be very useful as guidelines and development of policy in providing inclusive environment for the healthy lifestyle of building occupants

Five Myofibrillar Lesion Types in Eccentrically Challenged, Unloaded Rat Adductor Longus Muscle—A Test Model

Sarcomere disruptions are observed in the adductor longus (AL) muscles following voluntary reloading of spaceflown and hindlimb suspension unloaded (HSU) rat, which resemble lesions in eccentrically challenged muscle. We devised and tested an eccentric contraction (ECCON) test system for the 14-day HSU rat AL. Six to 7 hours following ECCON, ALs were fixed to allow immunostaining and electron microscopy (EM). Toluidine blue-stained histology semithin sections were screened for lesion density (#/mm2). Serial semithin sections from the ECCON group were characterized for myosin immunointensity of lesions. Five myofibrillar lesion types were identified in histological semithin sections: focal contractions; wide A-bands; opaque areas; missing A-bands; and hyperstretched sarcomeres. Lesion density by type was greater for ECCON than NonECCON ALs (P ≤ 0.05; focal contractions and opaque regions). Lesion density (#-of-all-five-types/mm2) was significantly different (ECCON: 23.91 ± 10.58 vs. NonECCON: 5.48 ± 1.28, P ≤ 0.05; ECCON vs. SHAM: 0.00 ± 0.00; P ≤ 0.025). PostECCON optimal tension decreased (Poi-drop, 17.84 ± 4.22%) and was correlated to lesion density (R2 = 0.596), but prestretch tension demonstrated the highest correlation with lesion density (R2 = 0.994). In lesions, the darkly staining A-band lost the normally organized thick filament alignment to differing degrees across the different lesion types. Ranking the five lesion types by a measure of lesion length deformation (hypercontracted to hyperstretched) at the light microscopy level, related to the severity of thick filament registry loss across the lesion types at the electron microscopic level. This ranking suggested that the five lesion types seen in semithin sections at the light level represented a lesion progression sequence and paralleled myosin immunostaining loss as the distorted A-band filaments spread across the hyperlengthening lesion types. Lesion ultrastructure indicated damage involved calcium homeostasis loss (focal contraction lesions) and “thick-filamentcentering” failure of titin (wide A-band lesions) in the early stages of lesion development

Rural Superintendent Turnover in Challenging Times: A Review of the Literature

The Covid-19 pandemic has shown a light on structural problems in education. Changing conditions, policy recommendations, and pressure from local communities have caused strain among educators and administrators across the nation. For rural districts already strained by shortages of teachers and administrators, the pandemic particularly raised alarms about the potential for accelerating superintendent turnover. By examining the superintendent turnover literature through the lens of district leadership roles and critical leadership of place, this review can support research to address superintendent turnover, provide guidance for preparation programs that aim to reduce the instability of rural district leadership, and the preparation of administrators for crisis situations

α2β1 integrin affects metastatic potential of ovarian carcinoma spheroids by supporting disaggregation and proteolysis

Background: Ovarian cancer is characterized by a wide-spread intra-abdominal metastases which represents a major clinical hurdle in the prognosis and management of the disease. A significant proportion of ovarian cancer cells in peritoneal ascites exist as multicellular aggregates or spheroids. We hypothesize that these cellular aggregates or spheroids are invasive with the capacity to survive and implant on the peritoneal surface. This study was designed to elucidate early inherent mechanism(s) of spheroid survival, growth and disaggregation required for peritoneal metastases.Methods: In this study, we determined the growth pattern and adhesive capacity of ovarian cancer cell lines (HEY and OVHS1) grown as spheroids, using the well established liquid overlay technique, and compared them to a normal ovarian cell line (IOSE29) and cancer cells grown as a monolayer. The proteolytic capacity of these spheroids was compared with cells grown as a monolayer using a gelatin zymography assay to analyze secreted MMP-2/9 in conditioned serum-free medium. The disaggregation of cancer cell line spheroids was determined on extracellular matrices (ECM) such as laminin (LM), fibronectin (FN) and collagen (CI) and the expression of &alpha;2, &alpha;3, &alpha;v, &alpha;6 and &beta;1 interin was determined by flow cytometric analysis. Neutralizing antibodies against &alpha;2, &beta;1 subunits and &alpha;2&beta;1 integrin was used to inhibit disaggregation as well as activation of MMPs in spheroids.Results: We demonstrate that ovarian cancer cell lines grown as spheroids can sustain growth for 10 days while the normal ovarian cell line failed to grow beyond 2 days. Compared to cells grown as a monolayer, cancer cells grown as spheroids demonstrated no change in adhesion for up to 4 days, while IOSE29 cells had a 2&ndash;4-fold loss of adhesion within 2 days. Cancer cell spheroids disaggregated on extracellular matrices (ECM) and demonstrated enhanced expression of secreted pro-MMP2 as well as activated MMP2/MMP9 with no such activation of MMP\u27s observed in monolayer cells. Flow cytometric analysis demonstrated enhanced expression of &alpha;2 and diminution of &alpha;6 integrin subunits in spheroidsversus monolayer cells. No change in the expression of &alpha;3, &alpha;v and &beta;1 subunits was evident. Conversely, except for &alpha;v integrin, a 1.5&ndash;7.5-fold decrease in &alpha;2, &alpha;3, &alpha;6 and &beta;1 integrin subunit expression was observed in IOSE29 cells within 2 days. Neutralizing antibodies against &alpha;2, &beta;1 subunits and &alpha;2&beta;1 integrin inhibited disaggregation as well as activation ofMMPs in spheroids.Conclusion: Our results suggest that enhanced expression of &alpha;2&beta;1 integrin may influence spheroid disaggregation andproteolysis responsible for the peritoneal dissemination of ovarian carcinoma. This may indicate a new therapeutic targetfor the suppression of the peritoneal metastasis associated with advanced ovarian carcinomas.<br /

Rural Superintendent Turnover in Challenging Times: A review of the literature

The Covid-19 pandemic has shown a light on structural problems in education. Changing conditions, policy recommendations, and pressure from local communities have caused strain among educators and administrators across the nation. For rural districts already strained by shortages of teachers and administrators, the pandemic particularly raised alarms about the potential for accelerating superintendent turnover. By examining the superintendent turnover literature through the lens of district leadership roles and critical leadership of place, this review can support research to address superintendent turnover, provide guidance for preparation programs that aim to reduce the instability of rural district leadership, and the preparation of administrators for crisis situations